Jenson Button completed a clean sweep of fastest practice times as he led the way in the final session before qualifying for the Japanese Grand Prix at Suzuka.
Friday pacesetter Button (McLaren) was quickest from the opening half of the session, commencing his morning with a 1m33.493s to go straight to the head of the order, then immediately improving to a 1m33.044s.
That stood until the Mercedes became the first frontrunners to try soft tires going into the final third of the hour, with first Nico Rosberg then Michael Schumacher leading the way as a consequence. But when Button put softs on, he blasted back to first position with a 1m31.255s, knocking Schumacher off the top spot by nearly 1.5sec.
None of Button's rivals could match that pace. His team-mate Lewis Hamilton ended up second quickest, half a second adrift. World Champion Sebastian Vettel was a low-key – by his standards – third for Red Bull, 0.8sec down on Button.
Fernando Alonso was the quickest Ferrari driver in fourth, ahead of the second Red Bull of Mark Webber and Ferrari's second driver Felipe Massa.
The Mercedes fell to seventh and eighth, followed by Vitaly Petrov (Renault) and Adrian Sutil (Force India).
Toro Rosso could not quite repeat its strong Friday performance, with its two cars ending the hour just outside the top 10.
After yesterday's litany of problems and incidents, Williams had a trouble-free session but was off the pace, with Pastor Maldonado and Rubens Barrichello down in 16th and 18th.
The session was interrupted by an eight-minute red flag when Bruno Senna crashed on the way out of Spoon 25 minutes in. The Renault ran wide on the exit and spun into the opposite barrier, hopping over its own left front wheel before coming to rest as the tethers prevented the wheel from detaching as the suspension smashed. Tonio Liuzzi's problems were less dramatic, as a drop in hydraulic pressure forced the HRT to stop on the circuit.
Pos Driver Team/Car Time Gap
1. Jenson Button McLaren-Mercedes 1m31.255s
2. Lewis Hamilton McLaren-Mercedes 1m31.762s + 0.507s
3. Sebastian Vettel Red Bull-Renault 1m32.122s + 0.867s
4. Fernando Alonso Ferrari 1m32.279s + 1.024s
5. Mark Webber Red Bull-Renault 1m32.401s + 1.146s
6. Felipe Massa Ferrari 1m32.429s + 1.174s
7. Michael Schumacher Mercedes 1m32.725s + 1.470s
8. Nico Rosberg Mercedes 1m32.878s + 1.623s
9. Vitaly Petrov Renault 1m33.058s + 1.803s
10. Adrian Sutil Force India-Mercedes 1m33.424s + 2.169s
11. Sebastien Buemi Toro Rosso-Ferrari 1m33.469s + 2.214s
12. Jaime Alguersuari Toro Rosso-Ferrari 1m33.545s + 2.290s
13. Kamui Kobayashi Sauber-Ferrari 1m33.818s + 2.563s
14. Sergio Perez Sauber-Ferrari 1m33.836s + 2.581s
15. Paul di Resta Force India-Mercedes 1m33.990s + 2.735s
16. Pastor Maldonado Williams-Cosworth 1m34.321s + 3.066s
17. Bruno Senna Renault 1m35.389s + 4.134s
18. Rubens Barrichello Williams-Cosworth 1m35.651s + 4.396s
19. Jarno Trulli Lotus-Renault 1m36.327s + 5.072s
20. Heikki Kovalainen Lotus-Renault 1m36.912s + 5.657s
21. Jerome D'Ambrosio Virgin-Cosworth 1m37.938s + 6.683s
22. Timo Glock Virgin-Cosworth 1m38.011s + 6.756s
23. Daniel Ricciardo HRT-Cosworth 1m38.355s + 7.100s
24. Tonio Liuzzi HRT-Cosworth 1m41.097s + 9.842s
All timing unofficial