Lewis Hamilton completed a Friday Practice double after topping a second session which was closely fought between McLaren, Lotus and Ferrari. Hamilton edged in front of Kimi Raikkonen by a tenth of a second during the option tyre runs but there was no time for any race simulations as heavy rain arrived halfway through the session.
Lotus were looking blistering quick right from the off with Romain Grosjean topping the early times but the Frenchman compromised his afternoon with a spin on the exit of the chicane at turn seven, swiping the front wing of his E20 against the barrier. While he limped back to the pits for repairs, teammate Raikkonen replaced him at the top of the leaderboard.
Kimi's benchmark time of a 1:22.950 remained unbeaten for several minutes with the two McLaren drivers slotting in behind less than a tenth adrift. The order was soon shaken up by the Ferraris as Fernando Alonso improved to a 1:22.899, only to be usurped by Felipe Massa, and the championship leader seemed set to improve further before pitting on his next lap.
With dark clouds looming large, everybody dived into the pits for a set of soft tyres and Jenson Button was the first to lay down a marker, clocking a 1:22.747, marginally quicker than Raikkonen's first lap on options, but Alonso bettered the pair of them, lowering the target time to a 1:22.582.
Lewis Hamilton eased off on his first attempt on the yellow-marked tyres despite setting the fastest first sector while Raikkonen produced a sensational lap to go four tenths quicker than Alonso, regaining first place. The Finn's main opposition now came in the form of Hamilton who was still setting purple sector times without stringing a perfect lap together. With 45 minutes of the session gone, he got it absolutely right with a 1:21.995 good enough to end the afternoon on top.
The feared rain, which many teams were expecting to be light, finally arrived within minutes of Hamilton's flier and it arrived in huge quantities, sending a slick-shod Heikki Kovalainen off the road at turn six. If any running was to take place now, it would have to be done on wet tyres.
Most opted for the intermediate Pirellis but standing water at turn eleven was proving too much for them. A number of drivers aquaplaned off there, including Bruno Senna who'd put his Williams up in a sensational third on the option tyres, while Timo Glock also explored the tarmac run-off area.
Michael Schumacher made it safely through that danger zone on the intermediates but the Mercedes driver skidded straight off at the next corner, locking the front wheels of his Mercedes at turn twelve. Schumacher's car hit the tyre wall nose first, bringing his session to an end with his car too damaged to continue.
With all quick times set in the dry, Hamilton finished at the top of the timesheets ahead of Raikkonen and the impressive Senna with Felipe Massa and Fernando Alonso taking fourth and fifth for Ferrari ahead of Jenson Button. Paul Di Resta was a strong seventh for Force India with Red Bull continuing to languish in the midfield. Sebastian Vettel was reasonably competitive in eighth but Mark Webber was visibly disappointed when he stepped out of his RB8, having only set the fourteenth fastest time. Between them were Romain Grosjean, the Mercedes pair of Schumacher and Nico Rosberg, Pastor Maldonado and Nico Hulkenberg.
Sauber were strangely off the pace this afternoon with Kamui Kobayashi and Sergio Perez fifteenth and eighteenth, sandwiching the two Toro Rossos, while Caterham, Marussia and HRT remained adrift at the bottom of the order.