Ahead of today's second free practice session, the air temperature is now 30 degrees C as is the track temperature.

When the lights go green, Rosberg leads the way, followed by Heidfeld, Alguersuari, Buemi and Liuzzi.

Rosberg aborts his first flying lap after losing time behind Fisichella, consequently he can only manage a 57.471 while Alguersuari posts 54.801.

After just six minutes there are ten names on the timesheets with Heidfeld leading the way, the German posting a 51.760. Indeed, German fill the first four places as Glock goes second ahead of Rosberg and Vettel.

Eight minutes into the session it's a Red Bull 1-2 as Vettel and Webber go quickest, the German posting a 50.958. Hamilton posts 51.549 to go third.

As Webber takes the top spot from Hamilton, Vettel does well to keep his car out of the barriers. Meanwhile, Kovalainen throws up a great cloud of sparks as his McLaren rides the unforgiving Singapore bumps.

No sooner has Heidfeld re-taken the spot than he is joined by Sutil and Vettel as the Germans continue to set the pace. Kubica and Grosjean are the only drivers who haven't been out yet.

Sutil posts 50.382 to go quickest, the Force India's off the pace in the earlier session. Elsewhere, a big slide from Alonso as the Spaniard struggles for grip on the dusty surface.

The tyre options this weekend are soft and super-soft though we've yet to see the softer option make an appearance, probably due to the amount of dust on the track.

Webber goes quickest in the first two sectors and again in the third, crossing the line at 49.317 to go quickest by 1.029s. Barrichello goes second ahead of Sutil, Alonso and Heidfeld.

Vettel is one of the first drivers to run on the super-soft compound and the German immediately goes second, just 0.304s off Webber's pace. In the Brawn garage mechanic are working on the front of Button's car.

Thirty-three minutes into the session the red flag comes out when Webber crashes on the pit straight. Exiting the final corner he loses the back end the car spinning across the track into the pit-wall. The Australian climbs out of the car, climbs through a gap in the fence and makes his way back to the Red Bull garage where a clearly frustrated Christian Horner is waiting for him.

When the session resumes Nico Rosberg heads the queue at the end of the pitlane. The German is now on super-softs.

A 49.507 sees Rosberg go second only to be almost instantly demoted by Nick Heidfeld who goes quickest with a 49.098. The BMW driver is also on the option tyre.

Button goes quickest in the second sector, finally crossing the line at 49.400 to go third, as more and more drivers switch to the super-soft tyre. Next time around the Englishman improves to second (49.311).

Glock loses time behind Barrichello, having gone quickest in the middle sector, and therefore can only manage seventh overall (49.853).

A beautiful slo-mo shot of Kovalainen riding the kerbs, the Finn now up to sixth 0.603s off the pace.

With thirty minutes remaining, it's: Heidfeld, Vettel, Button, Webber, Rosberg, Kovalainen, Glock, Sutil, Hamilton and Raikkonen. Fisichella is nineteenth, 2.596s off the pace.

Trulli improves to eighth with a 49.795 as the Renault crew work furiously on Alonso's car.

Grosjean, who has only completed 10 laps thus far, is back on track attempting to improve on twentieth (52.857). However, after just one lap he returns to the pits with a suspected brake problem.

Rosberg posts personal bests in all three sectors to go fifth (49.333), as Glock gets up close and personal with the wall.

With eleven minute remaining, Kovalainen goes quickest with a 48.952, the Finn looking mighty impressive here. Meanwhile, clearly going for reliability as opposed to times, Button completes his twenty-ninth lap, more than any other driver.

Vettel posts a 48.650 to go quickest as Hamilton goes quickest in the first sector. However, poor second and third sectors mean he only improves to seventh.