Ahead of today's all-important qualifying session, the air temperature is 28 degrees and the track temperature is 46 degrees.

In this morning's free practice session, the Top 17 were covered by just 1.093s, which indicated just how tight the field is here - a situation aided by the wild swings in performance courtesy of they tyres in the ever-changing temperatures. This morning's best times were set on the hard compound, and while the soft are expected to excel when it gets cooler, it will be interesting to see how they perform this afternoon.

While the close times promise a thrilling fight for pole, it will also mean that as in some previous qualifying sessions we may well see some major upsets, with 'big guns' missing the cut at the first hurdle.

While Brawn is expected to be up there at the end of the hour, along with Red Bull, keep an eye out for this morning's pace-setter, Felipe Massa, not to mention Toyota, Williams, McLaren, Renault and even BMW.

The lights go green and phase 1 gets underway, with Fisichella first out of the box. Shortly after, Buemi and Sutil are also on track.

Fisichella (on softs) posts the first time of the afternoon, crossing the line at 1:30.004. Sutil posts 29.393 and Buemi 29.646.

Raikkonen and Hamilton are the first of the big guns to come out, as Heidfeld goes quickest in the first sector. The German posts 28.794 to go quickest, but this is beaten by Raikkonen and then Trulli (28.267).

Massa (hards) is on track, as Nakajima goes quickest with a 28.190. The Brazilian, a winner here for the last three years, goes quickest with a 28.144, only for Rosberg to instantly demote him with a 27.980 before he too is bumped down by Vettel (27.784).

As Nakajima goes quickest, Raikkonen is on a hot lap, the Finn crossing the line at 7.687. Almost instantly the Ferrari driver is demoted by Trulli and then Vettel, it's fast and frantic.

Button goes third as Hamilton drops to thirteenth. With ten minutes remaining, all but Kubica and Piquet have posted times.

Barrichello is fifth for a brief moment before being demoted by Webber, who posts 27.678.

Barrichello improves to second and Massa fifth, both on the hard tyre. Buemi (softs) improves from twentieth to seventeenth. Kubica also improves, the Pole running on the harder compound.

With five minutes remaining, Heidfeld (softs) escapes the danger zone but only moves as high as twelfth.

Raikkonen is back on track, on softs, as is Hamilton, though the McLaren driver is on hards. The Englishman still in the danger zone, along with Piquet, Fisichella and the Toro Rossos.

Raikkonen makes a mistake and abandons the lap, as Hamilton doesn't look as though he is about to improve.