Rain curtails practice

The storm struck Sao Paulo 30 minutes before the hour-long session was scheduled to officially start, grounding the medical helicopter due to poor visibility and forcing the FIA to call a delay.

When the rain eventually eased off and motor sport's governing body announced an 11.42am local start time, there were still rivers of water around the Interlagos track. And it came as no surprise when the session was red flagged with five minutes remaining as Grosjean aquaplaned off the track and into a barrier.

The Frenchman had already spun once in his Renault, and although he managed to continue on that occasion, it was not long before he went one step further.

Fortunately, the impact with the barrier was not as severe as it could have been, although enough to send a marshal scurrying away in alarm.

The marshals were forced into a clear-up operation prior to the session as they used giant squeegees to sweep away the standing water, notably from the platform on which the helicopter stood.

With more rain forecast for qualifying later on Saturday, all 20 drivers used the limited amount of time available to put in a few laps on the extreme wet tyres.

Williams driver Nico Rosberg topped the timesheets after completing the most laps of any of his rivals, with the best of his nine a one minute 23.182secs, 11 seconds slower than the fastest in the dry on Friday from Fernando Alonso.

Rosberg finished 0.650secs ahead of his team-mate Kazuki Nakajima, followed by championship leader Jenson Button, Alonso and Adrian Sutil in his Force India, all just under a second down.