Australian Mark Webber put Red Bull on top of the times in final practice for the Chinese Grand Prix on Saturday.
The Red Bull driver set a best time of 1m35.323s to outpace yesterday's pace-setter Lewis Hamilton by over two tenths of a second ahead of this afternoon's qualifying.
Webber, however, was unable to match the time set by Hamilton in yesterday's second practice, the Briton's best still a tenth quicker.
Malaysian Grand Prix winner Sebastian Vettel was third fastest in the second Red Bull, the German just edging world champion Jenson Button as McLaren and Red Bull set what looks to be a thrilling battle for pole.
Fernando Alonso completed the top five in the Ferrari, but the Spaniard was already half a second off the pace set by Webber.
Team-mate Felipe Massa, meanwhile, had a more difficult morning and finished down in eighth after having to be pushed out of the pits for his final run.
Practice was red-flagged with some 17 minutes to go after Renault's Vitaly Petrov crashed at the start of the main straight, the F1 rookie going wide onto the AstroTurf and losing control of his car, impacting against the barriers and heavily damaging the front end of his Renault.
Although he was unhurt, the race director decided to stop practice in order for the debris to be cleared. The action was restarted with 10 minutes left on the clock.
The session had a quiet start, after all drivers returned to the pits for several minutes following their installation laps. Ten minutes into the hour-long session, Webber was only man not to have left the pits, the Australian finally jumping onto the track after over 15 minutes of the session were gone.
Petrov was the first driver to complete a timed lap after over 14 minutes, the Russian setting a 1m44.2s that was bettered by Virgin's Timo Glock moments later.
Championship leader Massa, and then team-mate Alonso, took to the top as the main contenders began their work some 20 minutes in, with Hamilton then outpacing the Ferrari duo before Webber set a 1m36.3s to put Red Bull at the head of the times.
Hamilton, quickest yesterday, was the only man to break into the 1:35s before the half-hour mark, with a lap that was around half a second slower than his Friday time. Webber then set his best time of the weekend to get within three tenths of the McLaren driver into second place.
There were no changes at the top of the times until the final rush on soft tyres began after the red flag, when Alonso moved into second before being demoted to fourth as the Red Bulls went quickest, with Webber just edging Vettel before going even quicker minutes later.
The session was mainly incident-free apart from Petrov's accident.
Pos Driver Team Time Laps
1. Webber Red Bull-Renault 1:35.323 16
2. Hamilton McLaren-Mercedes 1:35.564 + 0.241 12
3. Vettel Red Bull-Renault 1:35.691 + 0.368 14
4. Button McLaren-Mercedes 1:35.747 + 0.424 14
5. Alonso Ferrari 1:35.857 + 0.534 13
6. Rosberg Mercedes 1:35.913 + 0.590 12
7. Schumacher Mercedes 1:36.262 + 0.939 10
8. Kubica Renault 1:36.343 + 1.020 16
9. Massa Ferrari 1:36.416 + 1.093 11
10. Kobayashi Sauber-Ferrari 1:36.634 + 1.311 16
11. Alguersuari Toro Rosso-Ferrari 1:36.879 + 1.556 17
12. Liuzzi Force India-Mercedes 1:37.031 + 1.708 16
13. Buemi Toro Rosso-Ferrari 1:37.192 + 1.869 18
14. Sutil Force India-Mercedes 1:37.240 + 1.917 18
15. Petrov Renault 1:37.339 + 2.016 13
16. Barrichello Williams-Cosworth 1:37.585 + 2.262 13
17. de la Rosa Sauber-Ferrari 1:37.664 + 2.341 19
18. Hulkenberg Williams-Cosworth 1:37.784 + 2.461 14
19. Glock Virgin-Cosworth 1:39.579 + 4.256 15
20. Kovalainen Lotus-Cosworth 1:39.616 + 4.293 17
21. di Grassi Virgin-Cosworth 1:39.749 + 4.426 13
22. Trulli Lotus-Cosworth 1:39.776 + 4.453 16
23. Senna HRT-Cosworth 1:40.316 + 4.993 19
24. Chandhok HRT-Cosworth 1:41.141 + 5.818 18
All Timing Unofficial