Sebastian Vettel topped the final free practice session ahead of qualifying for the Abu Dhabi Grand Prix, leading another Red Bull one-two.
Vettel and the Lotus of Kimi Raikkonen took it in turns to top the times in the early going on the harder tyre.
Raikkonen was the first to dip under 1m44s, then Vettel moved ahead with a 1m43.795s.
Mark Webber went second fastest before Lewis Hamilton and Nico Rosberg moved to challenge the Red Bulls for Mercedes.
As track conditions improved, the duo moved ahead of Vettel just after the halfway mark, with Rosberg ahead.
Vettel and Rosberg then alternated in front, with Rosberg recording 1m43.465s with around 20 minutes to go.
Webber also moved ahead of Vettel, but the newly crowned world champion was set to improve before hitting traffic in the final sector.
Marussia driver Jules Bianchi then spun exiting Turn 1 and hit the barriers, preventing further improvements for several minutes.
Everyone subsequently switched to the softer Pirelli tyre for their low-fuel runs.
Button was the first to strike, with a lap in 1m41.956s. He was soon surpassed by Hamilton, but still ended up sixth as McLaren continued its decent Abu Dhabi form.
Vettel finally took the honours with a 1m41.349s lap, all but matching his best from free practice two, in the final three minutes.
Hamilton had a big moment at the last corner as he tried to improve, and ended up being pipped by a late charge from Webber.
Behind Rosberg, Romain Grosjean’s Lotus was fifth fastest, while both Saubers proved competitive, Nico Hulkenberg finishing seventh, one spot ahead of Esteban Gutierrez.
Raikkonen had a minor moment in the final 20 minutes and ended up ninth.
Ferrari continued to struggle on both the hard and soft tyres, Fernando Alonso ending up 11th, Felipe Massa 14th.
Pos Driver Team/Car Time Gap Laps 1. Sebastian Vettel Red Bull-Renault 1m41.349s 19 2. Mark Webber Red Bull-Renault 1m41.571s +0.222s 17 3. Lewis Hamilton Mercedes 1m41.580s +0.231s 18 4. Nico Rosberg Mercedes 1m41.721s +0.372s 19 5. Romain Grosjean Lotus-Renault 1m41.832s +0.483s 19 6. Jenson Button McLaren-Mercedes 1m41.956s +0.607s 19 7. Nico Hulkenberg Sauber-Ferrari 1m42.055s +0.706s 19 8. Esteban Gutierrez Sauber-Ferrari 1m42.282s +0.933s 19 9. Kimi Raikkonen Lotus-Renault 1m42.387s +1.038s 18 10. Jean-Eric Vergne Toro Rosso-Ferrari 1m42.457s +1.108s 21 11. Fernando Alonso Ferrari 1m42.516s +1.167s 15 12. Paul di Resta Force India-Mercedes 1m42.681s +1.332s 23 13. Valtteri Bottas Williams-Renault 1m42.698s +1.349s 19 14. Felipe Massa Ferrari 1m42.702s +1.353s 16 15. Daniel Ricciardo Toro Rosso-Ferrari 1m42.727s +1.378s 18 16. Pastor Maldonado Williams-Renault 1m42.798s +1.449s 18 17. Adrian Sutil Force India-Mercedes 1m42.989s +1.640s 22 18. Sergio Perez McLaren-Mercedes 1m43.142s +1.793s 15 19. Giedo van der Garde Caterham-Renault 1m44.472s +3.123s 20 20. Charles Pic Caterham-Renault 1m44.728s +3.379s 21 21. Max Chilton Marussia-Cosworth 1m45.621s +4.272s 20 22. Jules Bianchi Marussia-Cosworth 1m47.506s +6.157s 15