Fernando Alonso led the way for Ferrari in a dry final practice session ahead of British Grand Prix qualifying at Silverstone.
Jenson Button was the quickest McLaren driver in second, 0.153 seconds down on Alonso, with Romain Grosjean third for Lotus, and Sebastian Vettel (Red Bull), Kimi Raikkonen (Lotus) and Lewis Hamilton (McLaren) completing the top six.
With no dry running at all on Friday and dark clouds closing in, there was immediately a pitlane traffic queue to emulate the ones outside the circuit, with all teams eager to make the most of the conditions.
A sign of how much work was being crammed into the hour was that soft tyres runs began just after the mid-point, with Button the first to hit the front on softs, deposing team-mate Hamilton.
The McLarens swapped places again soon afterwards, as Hamilton took his turn on softs and produced a 1m32.728s to beat Button by 0.123s.
Grosjean then hinted at impressive pace from Lotus by beating the McLarens by three tenths on hard tyres, but his time in front was only fleeting as Alonso then delivered a 1m32.167s to head the order. The championship leader had a quick spin at Club on his next lap, continuing without drama and remaining at head of the times until the finish.
Button eventually reclaimed second, just ahead of Grosjean, who improved again on softs. The second Lotus of Raikkonen was fifth, between Vettel and Hamilton.
Pastor Maldonado was seventh for Williams, with Sergio Perez eighth despite smashing his Sauber's front wing as he bounced over the grass. Team-mate Kamui Kobayashi also had a spin before taking ninth, ahead of Nico Hulkenberg's Force India.
Mercedes' Nico Rosberg had been the initial pacesetter, but had to sit out the latter part of the session with a mechanical problem, so fell to 18th.
Also in mechanical bother was Marussia's Charles Pic. The Frenchman caused a brief red flag when his car ground to a halt on the exit of Copse just after the 20-minute mark. Marussia got it running again, but a similar thing seemed to happen in the closing minutes, leaving Pic stranded on the Hangar Straight.
Pos Driver Team Time Laps 1. Fernando Alonso Ferrari 1m32.167s 21 2. Jenson Button McLaren-Mercedes 1m32.320s + 0.153s 20 3. Romain Grosjean Lotus-Renault 1m32.358s + 0.191s 25 4. Sebastian Vettel Red Bull-Renault 1m32.420s + 0.253s 21 5. Kimi Raikkonen Lotus-Renault 1m32.454s + 0.287s 25 6. Lewis Hamilton McLaren-Mercedes 1m32.477s + 0.310s 20 7. Pastor Maldonado Williams-Renault 1m32.622s + 0.455s 21 8. Sergio Perez Sauber-Ferrari 1m32.940s + 0.773s 19 9. Kamui Kobayashi Sauber-Ferrari 1m33.046s + 0.879s 20 10. Nico Hulkenberg Force India-Mercedes 1m33.150s + 0.983s 19 11. Bruno Senna Williams-Renault 1m33.267s + 1.100s 25 12. Paul di Resta Force India-Mercedes 1m33.367s + 1.200s 20 13. Mark Webber Red Bull-Renault 1m33.398s + 1.231s 24 14. Michael Schumacher Mercedes 1m33.462s + 1.295s 24 15. Jean-Eric Vergne Toro Rosso-Ferrari 1m33.673s + 1.506s 22 16. Felipe Massa Ferrari 1m33.674s + 1.507s 21 17. Daniel Ricciardo Toro Rosso-Ferrari 1m33.707s + 1.540s 21 18. Nico Rosberg Mercedes 1m33.733s + 1.566s 15 19. Heikki Kovalainen Caterham-Renault 1m34.298s + 2.131s 18 20. Vitaly Petrov Caterham-Renault 1m34.781s + 2.614s 20 21. Timo Glock Marussia-Cosworth 1m36.605s + 4.438s 18 22. Charles Pic Marussia-Cosworth 1m37.060s + 4.893s 14 23. Narain Karthikeyan HRT-Cosworth 1m37.269s + 5.102s 23 24. Pedro de la Rosa HRT-Cosworth 1m37.429s + 5.262s 17 All Timing Unofficial