Sepang's main grandstand © Sutton

05:45 Welcome back to AUTOSPORT Live as we continue to follow the opening day of practice for the 2010 Petronas Malaysian Grand Prix.

The teams have moved on from Australia and set up their stalls ready for the third round of the season.

First practice took place this morning. Before the action resumes, we will look back on the earlier session, update you on the latest weather at the circuit and look at some of the finer details to emerge from an interesting morning at Sepang.

Lewis Hamilton topped the first session © Sutton

05:47 Lewis Hamilton left Melbourne five days ago feeling that he had driven the race of his life but got little reward. This morning, the Briton stamped his authority at the top of the timesheet, edging out team-mate Jenson Button and the Mercedes pairing of Nico Rosberg and Michael Schumacher.

The session started with a break from the norm, as Pedro de la Rosa dispensed with the traditional installation laps and concentrated on an immediate run with the update F-duct fitted to the Sauber C29. Formula 1 debutant Fariuz Fauzy took over for a short time as he got up to speed, before later battling with the Hispania entries of Senna and Chandhok.

Jaime Alguersuari raised the standard for a time, dipping under the 1m40s barrier before the big teams sent their drivers out for a run. Hamilton and Button fared best as they topped the list, but at Red Bull and Mercedes there were problems.

Sebastian Vettel had to cut short his second run with what he reported at the time to be a brake problem hampering his efforts, while Schumacher was sidelined for about an hour when problems were discovered after his installation lap.

Nico Rosberg split the McLaren pair at the end of the session, dropping Button to third and Schumacher to fourth. Robert Kubica was a strong fifth for Renault, with Mark Weber rounding out the top six.

05:49 A stray shower caused minor panic in the pitlane during the break between sessions. The track was doused by a short, sharp shower about one hour ago - but you wouldn't think so looking at the asphalt now.

The track is drying rapidly as we head towards second practice, but the airport radar tells us that further, more potent storms are on the way and may reach the circuit before the end of the session.

Fans show their colours © Sutton

05:51 Motor racing enthusiasts love to debate and discuss the action on track, and the live forum at the bottom of the screen is your chance to let everyone know your thoughts on events as they unfold at the circuit.

• Will the shower between the two practice sessions alter the balance of power at the top of the classification?

• Can Ferrari and Red Bull move up the order following a quiet morning?

• Do you want to see more rain, or would you prefer the second session to be dry?

Tell the world what you think.

Click the SHOW LIVE FORUM link in the red bar at the bottom of your browser window if you'd like to join the debate.

McLaren's aerodynamics could prove useful around Sepang © Sutton

05:53 Some notes after first practice:

• McLaren drivers topped all four speed traps during the first session at a circuit where the F-duct system provides maximum benefit - helping the team run more downforce for the tighter corners while blasting down the long straights with reduced drag.

• Kamui Kobayashi completed the most laps during the session - 28 - as Sauber looks to gather more data from its updated F-duct on the C29.

• Test drivers Fariuz Fauzy and Paul di Resta hand back the Lotus and Force India machines to their regular drivers for this afternoon. Malaysian Fauzy completed 19 laps on his competitive debut to end the session 22nd, 1.2s off Jarno Trulli.

• Crowd numbers are typically low on the first day at Sepang and this year is no exception - despite the race organisers offering free grandstand tickets and parking today.

05:55 Practice resumes at Sepang in five minutes.

05:56 The 47 Celsius track temperature has rapidly dealt with the moisture from that shower during the break.

05:58 The latest radar update from Kuala Lumpur International Airport tells us that a big storm is 100 kilometres to the east and advancing quickly towards the circuit.

0 min: The practice session is underway.

0 min: Lucas di Grassi and Heikki Kovalainen are the first men out this afternoon.

0 min: Mark Webber joins Kovalainen and di Grassi on the circuit.

1 min: Tonio Liuzzi heads out in the Force India. This will be his first chance to get out there, having handed his car over to Paul di Resta this morning.

1 min: Timo Glock is also out in his Virgin Racing machine.

2 min: Bruno Senna joins the early runners on track in the Hispania Racing entry.

2 min: Webber is immediately back into the pits after just a single lap in the Red Bull.

2 min: Di Grassi and Kovalainen are on to the first timed laps of the afternoon.

3 min: Toro Rosso sends Sebastien Buemi and Jaime Alguersuari onto the track to test out the track conditions.

4 min: Kovalainen starts the ball rolling with a 1m44.393s. Di Grassi betters that as he clocks 1m43.500s.

4 min: Tonio Liuzzi sets the fastest time so far - 1m38.679s.

5 min: Button, Alonso, Hamilton and Kubica are all heading around to get on with their afternoon's work.

6 min: Many drivers are out there on the circuit as the teams continue to watch the progress of a storm to the east. Buemi takes the fastest time with 1m36.926s.

7 min: Button slots in fourth quickest with a first attempt of 1m40.498s.

8 min: The new time to beat is a 1m34.954s from Hamilton.

8 min: Hamilton is on for a much quicker lap and is fastest through the first two sectors. He tops the final portion as well, despite a minor fumble in the final corner.

9 min: Buemi is pushed down to fourth with the recent times posted by Hamilton, Button and Kubica. Kobayashi is fifth so far.

9 min: Michael Schumacher has come out onto the track, as we see Vettel post 1m39.126s for 12th quickest.

9 min: Alonso is 12th quickest as the early order develops while team-mate Massa heads out for the first time this afternoon.

10 min: Adrian Sutil improves to fourth with a lap of 1m36.278s in the Force India.

11 min: Hamilton ups the pace once again with two fastest sectors but he's boxed behind Trulli's Lotus on the final straight and just fails to improve.

11 min: Schumacher and Mercedes team-mate Rosberg are now on their first timed efforts. They should move up the list very soon.

11 min: 20 cars are on track at the moment in a busy start to second practice.

12 min: Mark Webber is back out there following some changes. He initially went out at the start of the session but came in after just one lap.

13 min: Michael Schumacher is now 17th after posting a 1m40.740s. Rosberg slots in seventh with 1m36.575s.

13 min: Hamilton continues his struggles with traffic as he catches Chandhok's HRT. The Indian moves over as quickly as he can while the McLaren pits.

14 min: Glock tells his Virgin team that the car is bottoming around the lap.

15 min: Schumacher leaps up the order on the hard tyres from 18th to third quickest with a time of 1m35.681s. Hamilton still leads from Button.

15 min: At Renault, Kubica is fourth fastest fater the first run, with team-mate Petrov seventh.

17 min: Many of the leading drivers are in the pits at the moment with engineers pondering data from the first outing of the session.

17 min: Mark Webber is on his second timed lap of the session. His first effort placed him 18th .. and he stays there having backed off on this lap.

18 min: The Ferrari pair continue to circulate as they evaluate how the harder tyres work in race configuration.

18 min: Alonso is 15th and Massa 17th as they lap on a race fuel load.

19 min: Mark Webber is up to 15th with 1m38.840s. That is almost four seconds off Hamilton's leading pace, suggesting a high fuel run possibly.

21 min: Interesting to note that the Ferrari and Red Bull drivers are within four-tenths of a second of eachother, filling positions 15 to 18.

23 min: Di Grassi tells the Virgin team his recent set-up change has reduced understeer but he now has the tricky condition of snap oversteer.

23 min: Sebastien Buemi on the other hand, is going for it. He is ninth and marginally improves with a 1m36.727s.

23 min: Hamilton and Kubica are back on track for more running.

24 min: Once again, Nico Rosberg split the McLaren drivers before pitting. The order is as it was at the end of the first session, with Hamilton at the top, from Rosberg, Button and Schumacher.

25 min: Massa improves his time as his lengthy run on hard rubber continues. His 1m39.088s remains 17th fastest, just behind team-mate Alonso.

26 min: Virgin is watching the skies: "Timo concerned that rain is coming before the end of the session"

26 min: Hamilton is straight back to setting the pace as he resumes with a new benchmark of 1m34.765s.

26 min: Adrian Sutil moves up a place to fifth with a lap of 1m35.968s in the Force India.

29 min: Michael Schumacher is slowly moving towards the top of the pile. He is second only to Hamilton now after posting 1m35.309s.

29 min: Kubica takes that fifth place back for his Renault with a 1m35.825s.

30 min: Jaime Alguersuari moves up several positions to eighth with a time of 1m36.325s in the Toro Rosso.

30 min: Kubica is still on hard rubber and lapping in the 1m35s bracket.

31 min: Replays show hefty right rear graining on Jenson Button's McLaren.

31 min: The weather to the east paints a gloomy picture. The storm we mentioned earlier is now 75 km away and closing in.

31 min: Mark Webber slows down and pulls off the track at Turn 9.

32 min: The Australian clearly had a technical problem wit the Red Bull and chose to pull off into a gravel trap to prevent further damage.

33 min: Replays indicate that the RB6 suffered a sudden loss of power as Webber accelerated towards the tight left-hander. Webber is now walking away as the safety crew removes the car to a safer position.

34 min: Nico Rosberg is up to second place ahead of team-mate Schumacher with a lap of 1m35.145s. He is 0.380s shy of Hamilton's time.

35 min: Rosberg was set to go even quicker, but he lost time following Bruno Senna in the final sector of the lap.

36 min: The Mercedes driver was running a set of soft tyres, but unfortunately hasn't been able to use the best of them thanks to the Webber incident and traffic.

36 min: Ferrari mechanics are making rear suspension adjustments on Massa's car ahead of the Brazilian's next run.

37 min: Alonso, meanwhile, is already out to test the softer tyres.

37 min: Sebastien Buemi has vaulted up the standings to fifth position with a lap of 1m35.660s. Team-mate Alguersuari is ninth currently.

38 min: Alonso clocks a 1m38.637s on his soft tyres to move up to 15th, with the Ferrari likely to be testing long run pace on that rubber.

39 min: Robert Kubica has also swapped to the softer rubber and also has visible graining on his right rear tyre.

40 min: These hot track temperatures and high-speed corners are clearly punishing the tyres today, but this should improve as the track gains rubber

40 min: Sebastian Vettel comes into the pits at the end of a run that concentrated on race work, rather than ultimate pace. He is 17th currently.

41 min: Kubica is on a strong pace in the Renault as he improves his sixth-placed time with a 1m35.706s.

42 min: The latest information from Kuala Lumpur International Airport tells us that showers are now less than 50 km away from the circuit.

43 min: Hamilton is back on track in his McLaren and is fastest through the first sector.

44 min: Meantime, Michael Schumacher is using a set of soft tyres to the maximum. He goes quickest with a time of 1m34.674s.

44 min: A quick second sector for the McLaren topples Schumacher from the top of the times as Hamilton completes the lap in 1m34.27s on the softs.

45 min: Button is also evaluating the softer rubber on his McLaren and is now starting a flying lap.

46 min: Clouds continue to build from the east and there is now a general haze to the sunshine.

46 min: So Lewis Hamilton leads the standings with a new benchmark of 1m34.276s ahead of Schumacher, Rosberg, Kubica and Button after 47 minutes.

46 min: Button is on for his best lap of the afternoon, while Hamilton is again setting fastest sectors.

47 min: Button clocks a 1m34.538s in his McLaren to go second quickest to team-mate Hamilton.

48 min: Hamilton improves by a tenth with a new benchmark time of 1m34.175s.

48 min: The pacesetter is telling his team that the upshift of the gearbox is a little aggressive and it is causing wheelspin.

49 min: Nico Rosberg is back out for another run in the Mercedes and is immediately quick on soft tyres. He is fourth at the moment.

50 min: Rosberg posts the fastest first sector of all and backs that up with a personal best in sector two. He is set to improve ...

51 min: Rosberg also posts a personal best in the final portion of the lap, but it isn't enough to demote Hamilton - 1m34.443s keeps him second.

51 min: Both McLarens have pitted after short runs on the softer tyres, indicating the team may be working towards qualifying pace at the moment.

52 min: Tonio Liuzzi moves up the order from 13th to 12th with 1m36.360s as his team-mate Sutil runs wide and into the gravel at Turn 12.

53 min: Sutil recovers back onto the circuit and will stay out for another go at a quick time.

53 min: The Ferrari duo continue lengthy runs on the softer tyres with collecting data on race durability the aim.

53 min: Sebastian Vettel has lightened the load and has a set of soft tyres bolted onto the Red Bull. He moves up to fifth with 1m34.863s.

54 min: Rubens Barrichello is another driver set to improve. He goes 14th with a time of 1m36.813s in the Williams.

55 min: Sebastian Vettel is still circulating on the soft tyres, but reports on the team radio that he is having a problem with the power steering.

57 min: Nico Rosberg came back into the pits after that short run of laps in the Mercedes. As he was pushed back into the garage, we could see signs of light graining on the right rear.

58 min: Vettel backed off for a lap while the telemetry engineers checked over the power steering data. He has since been given the all clear.

59 min: Vettel takes full advantage of the all-clear signal from his team, and posts the second fastest time - 1m34.441s.

59 min: While Vettel was on that improving lap, we saw Jaime Alguersuari and Sebastien Buemi both have minor off-track excursions. Both continued.

60 min: At the tail end of the timesheet, Trulli has a strong lead in the new team battle with the 16th fastest time for Lotus. Kovalainen is 20th from di Grassi, Glock, Senna and Chandhok.

60 min: Mark Webber's Red Bull Renault has arrived back in the pits. It has been wheeled into the garage.

61 min: Jaime Alguersuari is having a world of adventure on this run. He is off the track again - this time at Turn 6. He continues.

62 min: Alguersuari will be hoping for a clean lap as he continues testing the soft tyres. He is 13th at the moment.

62 min: Sebastian Vettel is back in the pits at the end of that run on the soft tyre. He is told by his race engineer that the data didn't show anything wrong with the power steering system.

63 min: De la Rosa is testing the softer tyres on his Sauber. The Spaniard is currently 12th fastest.

65 min: The drivers continue to pound around the circuit with long runs to evaluate the tyres ahead of the race.

65 min: Hamilton is back out with his used soft tyres and may plan to test with a little more fuel onboard than when he set the benchmark time.

65 min: The latest news on the rain showers is that the closest downpour is now less than 25 km away from the circuit.

66 min: Bruno Senna runs wide at Turn 14 and takes the scenic route through the gravel. He recovers and has pitted the Hispania Racing entry.

67 min: At the head pf the field, Lewis Hamilton leads the way with 1m34.175s ahead of Vettel, Rosberg, Button and Schumacher. Kubica is sixth.

67 min: Timo Glock is the next man to try an alternative line through the troublesome Turn 12. The Virgin clatters over the kerb but the German is able to scoop up the moment on the exit.

69 min: Massa is still lapping on a set of the softer tyres, despite a quick visit to the pits to gather more crucial data for Ferrari.

70 min: Hamilton is well off his earlier pace in what does now seem to be a heavily-fuelled McLaren. Team-mate Button looks to be on a similar plan.

70 min: Nico Rosberg is back out on the circuit but possibly running with a high fuel load as he works towards the race.

71 min: Rosberg's sector times are similar to the McLaren duo

71 min: Massa sets his best time of the afternoon in a 1m38.603s but remains down in 19th while looking towards the race.

73 min: Massa pops in for another run through the pitlane and is back underway again.

73 min: Lap time improvements and position changes are non-existent currently as the teams work towards the race. The race on Sunday begins at 16:00 and it is now 15:14 local time.

74 min: Alonso is on used soft tyres for his latest effort and is set to move up the order, perhaps finally with a lighter F10.

75 min: Alonso indeed moves forward with a 1m35.851s to go seventh.

76 min: Button tells his McLaren team that he generally has understeer on his used rubber but also has instability at the rear - perhaps caused by the evident graining of the right rear tyre.

77 min: The airport radar suggests to us that there could be rain for approximately the last five minutes of the session.

78 min: Alonso pits after a short run that put him seventh quickest.

79 min: Behind the shower that we have been watching, further convective storm showers are building to the east of the circuit. We will have a full weather update later today following practice.

80 min: Conditions are now fully overcast with just under ten minutes remaining today.

82 min: Hamilton and Button continue to collect long-run data for McLaren on the softer tyres, which they will hope to run in the first stint of the race.

83 min: Kubica is on a final outing with the harder tyres on his Renault.

84 min: The track temperature has dipped to 42 degrees under increasingly threatening skies.

84 min: Nico Rosberg and Sebastian Vettel are also continuing round with a reasonably heavy load of fuel with just five minutes remaining.

84 min: 20 cars are on track to get as many laps as possible completed before the flag.

85 min: Alonso is also making a quick evaluation of the harder rubber while Ferrari mechanics work on Massa's car.

86 min: Massa is now heading out on track, with only Petrov and the sidelined Webber still in the pits.

87 min: Nico Hulkenberg is finding good pace in the first sector of the lap, but then loses time in the second and third sectors of the lap. He remains in 16th position.

87 min: Massa is weaving on the final straight to warm the tyres before starting a flyer on soft rubber.

88 min: Massa looks set for an improvement from his current 19th quickest.

89 min: Karun Chandhok - perhaps with a lighter fuel load - improves by some three seconds and goes 23rd with a lap of 1m41.394s.

89 min: Massa improves to 15th with a 1m36.602s.

07:31 The flag is out to end the first day of practice in Malaysia.

07:32 Karun Chandhok finds another three-tenths of a second with a lap of 1m41.084s. He remains in 23rd position, ahead of Senna.

07:33 Lewis Hamilton was quickest in the second practice session at Sepang with a quickest lap of 1m34.175s. Sebastian Vettel was second.

07:33 Nico Rosberg ends up third fastest, just 0.002s behind Vettel, with Jenson Button fourth and Michael Schumacher in fifth spot.

07:35 Robert Kubica gives Renault a good day with sixth, less than one second off the pace. Alonso was the quickest Ferrari driver in seventh.

07:35 Sebastien Buemi was eighth for Toro Rosso with Petrov ninth and Sutil rounding out the top ten at the end of a very busy session.

07:37 The showers managed to dodge their way round Sepang this afternoon. Rain currently lies just a few miles to the south of the circuit.

07:40 We will have a full update on the weather prospects for the weekend later today on the Malaysian Grand Prix Weather page.

07:42 Here is the report following an interesting session:

Hamilton fastest again in second practice

07:45 Lewis Hamilton ruled Sepang on Friday with good one-lap pace and a strong run during race-related runs on higher fuel.

The teams managed to get through a lot of work today and will be keen to study the data and make the best use of it tomorrow for final practice and qualifying.

Will McLaren stay on top or can Mercedes, Ferrari and Red Bull charge through to the front? Join us for full coverage of the final practice session from Sepang at 04:45 GMT on Saturday.