Sebastian Vettel was fastest again in final practice ahead of Singapore Grand Prix qualifying, but Romain Grosjean and Lotus stepped up to pressure Red Bull.
There were hints throughout the session that Red Bull's rivals had reduced the advantage it held at the end of Friday. Red Bull again held a 1-2 during the main running on the harder Pirellis. This time Mark Webber turned the tables on Vettel after their Friday battle as his 1m46.220s lap beat the German by 0.079 of a second.
Lewis Hamilton's Mercedes was just 0.2sec slower, a notable improvement on practice two.
Again there were substantial pace improvements on the super-soft tire, with a massive leap from Grosjean putting the Lotus on top with a 1m44.364s.
Vettel managed to still pip that with a 1m44.173s, 0.191sec faster, while Webber hit traffic on super-softs and was only fourth behind Mercedes' Nico Rosberg.
Hamilton ended the hour in fifth ahead of Fernando Alonso's Ferrari. Alonso was followed by the man McLaren would perhaps like to oust in his favor next year: Sergio Perez.
Nico Hulkenberg gave Sauber another boost with eighth place, with Jenson Button and Felipe Massa completing the top 10.
While Grosjean starred, his Lotus teammate Kimi Raikkonen could only manage 12th with a disappointing super-soft attempt.
Pos Driver Team/Car Time Gap Laps
1. Sebastian Vettel Red Bull-Renault 1m44.173s 15
2. Romain Grosjean Lotus-Renault 1m44.364s +0.191s 16
3. Nico Rosberg Mercedes 1m44.741s +0.568s 18
4. Mark Webber Red Bull-Renault 1m44.906s +0.733s 14
5. Lewis Hamilton Mercedes 1m44.921s +0.748s 14
6. Fernando Alonso Ferrari 1m45.257s +1.084s 13
7. Sergio Perez McLaren-Mercedes 1m45.500s +1.327s 12
8. Nico Hulkenberg Sauber-Ferrari 1m45.876s +1.703s 19
9. Jenson Button McLaren-Mercedes 1m45.890s +1.717s 13
10. Felipe Massa Ferrari 1m45.935s +1.762s 13
11. Jean-Eric Vergne Toro Rosso-Ferrari 1m46.084s +1.911s 15
12. Kimi Raikkonen Lotus-Renault 1m46.147s +1.974s 13
13. Pastor Maldonado Williams-Renault 1m46.338s +2.165s 17
14. Daniel Ricciardo Toro Rosso-Ferrari 1m46.358s +2.185s 16
15. Valtteri Bottas Williams-Renault 1m46.660s +2.487s 17
16. Paul di Resta Force India-Mercedes 1m46.879s +2.706s 16
17. Esteban Gutierrez Sauber-Ferrari 1m46.893s +2.720s 13
18. Adrian Sutil Force India-Mercedes 1m47.249s +3.076s 19
19. Giedo van der Garde Caterham-Renault 1m48.931s +4.758s 17
20. Charles Pic Caterham-Renault 1m49.037s +4.864s 18
21. Jules Bianchi Marussia-Cosworth 1m49.182s +5.009s 21
22. Max Chilton Marussia-Cosworth 1m49.982s +5.809s 20