Renault's Fernando Alonso overshadowed the championship combatants again in final practice at Interlagos, beating Lewis Hamilton into second place with his final lap.
Hamilton's McLaren teammate Heikki Kovalainen took third, with Felipe Massa (Ferrari) having to settle for fourth position.
The title rivals moved to the front as soon as they started their first runs, quickly pushing previous pace-setters Kovalainen and Kimi Raikkonen (Ferrari) back to third and fourth.
Hamilton was immediately quicker than Massa, lapping in 1:12.278 compared to the Brazilian's 1:12.427.
But they then found it hard to improve on those times, both making minor errors in the middle sector on their next laps. Hamilton would improve his first sector time on a subsequent outing, only to lose nearly two seconds with another mistake in sector two, while Massa had fewer dramas on his next run but was still a few fractions slower than his earlier mark.
When they switched to soft tyres for the final qualifying simulations, it was McLaren who fared better. Kovalainen briefly went fastest, before Hamilton beat his time by 0.013 seconds, despite encountering traffic in the middle sector.
Massa was within a few thousandths of a second of Hamilton's pace for the first two-thirds of his own soft tyre lap, but lost out in the final sector - crossing the line exactly one tenth slower than his championship opponent.
But then in a repeat of yesterday afternoon's session, Alonso vaulted from the midfield with his last gasp low fuel run and outshone the title rivals. The Spaniard's 1:12.141 beat Hamilton by 0.071 seconds, pushing Kovalainen and Massa back to third and fourth.
Toro Rosso had a very strong session, challenging for the top six throughout and eventually taking fifth and seventh places with Sebastian Vettel and Sebastien Bourdais. They were split by BMW's Nick Heidfeld.
Mark Webber took eighth for Red Bull, ahead of Nelson Piquet's Renault and Jarno Trulli's Toyota.
Raikkonen ended up only 12th in the second Ferrari, having failed to improve on his soft tyre run.
Pos Driver Team Time Laps 1. Alonso Renault (B) 1:12.141 19 2. Hamilton McLaren-Mercedes (B) 1:12.212 + 0.071 18 3. Kovalainen McLaren-Mercedes (B) 1:12.225 + 0.084 18 4. Massa Ferrari (B) 1:12.312 + 0.171 17 5. Vettel Toro Rosso-Ferrari (B) 1:12.389 + 0.248 19 6. Heidfeld BMW Sauber (B) 1:12.402 + 0.261 19 7. Bourdais Toro Rosso-Ferrari (B) 1:12.426 + 0.285 18 8. Webber Red Bull-Renault (B) 1:12.453 + 0.312 18 9. Piquet Renault (B) 1:12.457 + 0.316 24 10. Trulli Toyota (B) 1:12.457 + 0.316 19 11. Rosberg Williams-Toyota (B) 1:12.625 + 0.484 16 12. Raikkonen Ferrari (B) 1:12.698 + 0.557 18 13. Glock Toyota (B) 1:12.712 + 0.571 22 14. Kubica BMW Sauber (B) 1:12.971 + 0.830 22 15. Nakajima Williams-Toyota (B) 1:13.054 + 0.913 19 16. Coulthard Red Bull-Renault (B) 1:13.058 + 0.917 22 17. Barrichello Honda (B) 1:13.135 + 0.994 24 18. Button Honda (B) 1:13.278 + 1.137 23 19. Fisichella Force India-Ferrari (B) 1:13.460 + 1.319 22 20. Sutil Force India-Ferrari (B) 1:13.680 + 1.539 22 All timing unofficial