Robert Kubica waited until two and a half minutes from the end of the final free practice session at Valencia to become the first man to break into 1:38s bracket this weekend, and go fastest of all in the hour.
As ever, the final few moments of the session were frantic, but for much of practice it looked distinctly as if the Scuderia Toro Rosso pair of Sebastian Vettel and Sebastien Bourdais might sweep the top spots.
Eventually, the Frenchman ended the session third, behind Nico Rosberg, who produced an inspired lap to take the chequered flag second.
And as if to prove the Williams team's pace this weekend, Kazuki Nakajima was fourth.
Felipe Massa was fifth for Ferrari, having been tumbled by the late carousel of times, which also dropped Vettel to sixth.
Lewis Hamilton, who completed the least amount of laps of the runners without problems and was seventh after an error-strewn session that saw him spin through 360 degrees at Turns 4 and 5.
Nick Heidfeld was eighth, ahead of David Coulthard, while Nelson Piquet completed the top ten having been fastest four minutes before the end of the session.
Jenson Button did well to recover to 12th, behind Mark Webber, after an early hydraulic issue, while home hero Fernando Alonso could only manage 13th after his late flyer was ruined by a lock-up.
Heikki Kovalainen and Kimi Raikkonen never really featured in 14th and 15th. The Toyotas were disappointing too; Timo Glock was 16th, while Jarno Trulli's troubles continued as he completed just two laps with what is believed to be a gearbox problem.
Pos Driver Team Time Laps 1. Kubica BMW Sauber (B) 1:38.754 15 2. Rosberg Williams-Toyota (B) 1:38.877 + 0.123 18 3. Bourdais Toro Rosso-Ferrari (B) 1:39.009 + 0.255 16 4. Nakajima Williams-Toyota (B) 1:39.270 + 0.516 17 5. Massa Ferrari (B) 1:39.276 + 0.522 18 6. Vettel Toro Rosso-Ferrari (B) 1:39.300 + 0.546 16 7. Hamilton McLaren-Mercedes (B) 1:39.314 + 0.560 13 8. Heidfeld BMW Sauber (B) 1:39.335 + 0.581 18 9. Coulthard Red Bull-Renault (B) 1:39.421 + 0.667 16 10. Piquet Renault (B) 1:39.452 + 0.698 20 11. Webber Red Bull-Renault (B) 1:39.597 + 0.843 17 12. Button Honda (B) 1:39.628 + 0.874 10 13. Alonso Renault (B) 1:39.652 + 0.898 17 14. Kovalainen McLaren-Mercedes (B) 1:39.802 + 1.048 14 15. Raikkonen Ferrari (B) 1:39.810 + 1.058 20 16. Glock Toyota (B) 1:39.919 + 1.165 22 17. Sutil Force India-Ferrari (B) 1:40.019 + 1.265 21 18. Fisichella Force India-Ferrari (B) 1:40.059 + 1.305 21 19. Barrichello Honda (B) 1:40.512 + 1.758 20 20. Trulli Toyota (B) no time 2