Button on top in final practice
Jenson Button kept McLaren on top of the time-sheets when he clocked the fastest lap in Saturday morning's third and final free practice session ahead of this weekend's title showdown Brazilian Grand Prix.
The 32-year-old Briton took over from teammate and compatriot Lewis Hamilton, who had topped the times in both sessions on Friday as hot and humid weather replaced the blue skies and McLaren continued to upstage the championship protagonists.
Defending champion Germany's Sebastian Vettel, who needs to finish fourth or better to be certain of becoming the youngest triple champion in Formula One hitory, was second fastest ahead of his Red Bull teammate Australian Mark Webber.
Button's McLaren teammate Hamilton was fourth fastest in a closely-fought session that saw the top four drivers separated by only two-tenths of a second.
Vettel's only remaining title rival, two-time champion Spaniard Fernando Alonso of Ferrari, was eighth-fastest for Ferrari and his teammate and local hero Brazilian Felipe Massa was down in 10th.
Button clocked his fastest lap of one minute and 13.188 seconds in the closing seconds of the session after earlier topping the times with a quick lap in the 18th minute of the hour's high-temp action.
Frenchman Romain Grosjean of Lotus was fifth ahead of Briton Paul Di Resta and his Force India teammate German Nico Hulkenberg. Venezuelan Pastor Maldonado was ninth for Williams.
The session was run in sultry heat with a track temperature of 36 degrees Celsius and an air tepmperature of 28 degrees.
Finn Kimi Raikkonen, winner of the Abu Dhabi Grand Prix this year, was forced to retire from the fray after only 14 minutes when the Renault engine in his Lotus car failed.
1. Jenson Button (Britain) McLaren 1:13.188
2. Sebastian Vettel (Germany) RedBull - Renault 1:13.245
3. Mark Webber (Australia) RedBull - Renault 1:13.385
4. Lewis Hamilton (Britain) McLaren 1:13.389
5. Romain Grosjean (France) Lotus - Renault 1:13.420
6. Paul Di Resta (Britain) Force India - Mercedes 1:13.486
7. Nico Huelkenberg (Germany) Force India - Mercedes 1:13.602
8. Fernando Alonso (Spain) Ferrari 1:13.691
9. Pastor Maldonado (Venezuela) Williams - Renault 1:13.700
10. Felipe Massa (Brazil) Ferrari 1:13.712
11. Bruno Senna (Brazil) Williams - Renault 1:13.948
12. Nico Rosberg (Germany) Mercedes 1:14.126
13. Sergio Perez (Mexico) Sauber - Ferrari 1:14.190
14. Kamui Kobayashi (Japan) Sauber - Ferrari 1:14.192
15. Michael Schumacher (Germany) Mercedes 1:14.347
16. Daniel Ricciardo (Australia) Toro Rosso - Ferrari 1:14.687
17. Jean-Eric Vergne (France) Toro Rosso - Ferrari 1:14.972
18. Vitaly Petrov (Russia) Caterham - Renault 1:15.159
19. Heikki Kovalainen (Finland) Caterham - Renault 1:15.707
20. Timo Glock (Germany) Marussia - Cosworth 1:15.763
21. Charles Pic (France) Marussia - Cosworth 1:16.059
22. Pedro de la Rosa (Spain) HRT - Cosworth 1:16.198
23. Narain Karthikeyan (India) HRT - Cosworth 1:16.793
24. Kimi Raikkonen (Finland) Lotus - Renault No Time