McLaren driver Lewis Hamilton beat Ferrari's Felipe Massa to the fastest time in the final free practice session for the French Grand Prix.
At the same time, Hamilton's teammate Fernando Alonso ended up only eighth after mechanical problems forced him to miss all bar the last two minutes of the hour.
Kimi Raikkonen took third in the second Ferrari, ahead of the two Renaults.
The session was briefly interrupted after 25 minutes when a section of grass from the inside of the final chicane became detached and was dragged onto the circuit. A seven-minute red flag stoppage was required while the debris was removed.
Raikkonen was the only one of the top four drivers who managed to complete a final lap before the red flag.
Massa immediately claimed the top spot when the session resumed, beating his teammate by 0.203 seconds and then finding another 0.015 seconds on his second lap.
Ten minutes later, Massa came back out to raise the bar again, lapping in 1:15.031 and pulling four tenths of a second clear of the field.
Hamilton briefly moved into second before Raikkonen reclaimed the place two minutes later. The Finn then set a new fastest first sector time on his next lap, but encountered Alex Wurz at the Chateau d'Eau and abandoned the run.
Then with five minutes to go, Hamilton switched to the softer compound and went fastest, lapping in 1:14.843. Massa responded and improved his best time, but remained 0.063 seconds adrift.
Apart from an early installation lap, Alonso remained in the McLaren garage throughout all of this action, with the mechanics working on his car.
He finally joined the session in the final two minutes, and only managed a single flying lap. He was classified eighth, 0.899 seconds behind his teammate.
Heikki Kovalainen was closest to the top three for the majority of the session and took fourth, half a second off the pace, and a tenth ahead of Renault teammate Giancarlo Fisichella.
Robert Kubica and Nico Rosberg were sixth and seventh, ahead of the troubled Alonso. Jarno Trulli and David Coulthard completed the top ten.
Vitantonio Liuzzi and Jenson Button had run as high as fifth in the middle of the session, but as others improved in the final rush, the Toro Rosso and Honda were pushed down to 11th and 12th respectively.
Pos Driver Team Time Laps 1. Hamilton McLaren-Mercedes (B) 1:14.843 8 2. Massa Ferrari (B) 1:14.906 + 0.063 16 3. Raikkonen Ferrari (B) 1:15.276 + 0.433 15 4. Kovalainen Renault (B) 1:15.404 + 0.561 19 5. Fisichella Renault (B) 1:15.489 + 0.646 20 6. Kubica BMW Sauber (B) 1:15.535 + 0.692 20 7. Rosberg Williams-Toyota (B) 1:15.735 + 0.892 18 8. Alonso McLaren-Mercedes (B) 1:15.742 + 0.899 4 9. Trulli Toyota (B) 1:15.801 + 0.958 19 10. Coulthard Red Bull-Renault (B) 1:15.802 + 0.959 15 11. Liuzzi Toro Rosso-Ferrari (B) 1:15.872 + 1.029 22 12. Button Honda (B) 1:15.902 + 1.059 16 13. Davidson Super Aguri-Honda (B) 1:15.925 + 1.082 20 14. R.Schumacher Toyota (B) 1:15.944 + 1.101 22 15. Heidfeld BMW Sauber (B) 1:16.060 + 1.217 18 16. Barrichello Honda (B) 1:16.102 + 1.259 19 17. Wurz Williams-Toyota (B) 1:16.104 + 1.261 16 18. Speed Toro Rosso-Ferrari (B) 1:16.161 + 1.318 18 19. Sato Super Aguri-Honda (B) 1:16.221 + 1.378 18 20. Webber Red Bull-Renault (B) 1:16.573 + 1.730 14 21. Sutil Spyker-Ferrari (B) 1:17.517 + 2.674 21 22. Albers Spyker-Ferrari (B) 1:17.705 + 2.862 23 All timing unofficial