Nico Rosberg topped the timesheets in a shortened 18-minute final practice session for the Brazilian Grand Prix as heavy rain continues to fall in Interlagos.
The final practice session had been scheduled to start at 1100 local time but a heavy deluge half an hour before the start of the session rendered track too dangerous for the cars to go out.
The rain gradually began to ease and race control announced a shortened 18-minute session, starting at 1142 to give the teams and drivers experience of the conditions ahead of qualify.
Heikki Kovalainen laid down a benchmark time of 1m31.716s which was smashed by Nico Rosberg as the two drivers traded fastest lap times.
The session was stopped with three minutes remaining after Romain Grosjean aquaplaned off the circuit at Curva do Lago and smashed into the barriers.
Rosberg ended the session in P1 on a 1.23.182 ahead of his Williams teammate Kazuki Nakajima.
Jenson Button was third quickest ahead of Fernando Alonso, Adrian Sutil and Sebastian Beumi.
Temperatures today will rise to a high of 23°C, and there remains a 60% chance of rain during qualifying.
1 Nico Rosberg Williams 1:23.182
2 Kazuki Nakajima Williams 0:00.650
3 Jenson Button Brawn 0:00.940
4 Fernando Alonso Renault 0:00.943
5 Adrian Sutil Force India 0:00.967
6 Sebastien Buemi Toro Rosso 0:01.261
7 Jarno Trulli Toyota 0:01.677
8 Heikki Kovalainen McLaren 0:02.503
9 Nick Heidfeld BMW 0:03.221
10 Romain Grosjean Renault 0:04.028
11 Lewis Hamilton McLaren 0:04.616
12 Vitantanio Liuzzi Force India 0:05.253