McLaren's Lewis Hamilton headed team-mate Jenson Button and Red Bull's Sebastian Vettel in Abu Dhabi Grand Prix final practice.
Hamilton set the pace throughout, but Vettel was impressive in third after spending all but five minutes of the session in the pits.
Ferrari's Fernando Alonso, Vettel's title rival, appeared to struggle and was only eighth, a second off the pace.
Red Bull's Mark Webber was fourth ahead of Force India's Nico Hulkenberg.
Lotus driver Romain Grosjean was sixth, ahead of Williams's Pastor Maldonado. Behind Alonso, Grosjean's team-mate Kimi Raikkonen was ninth ahead of Force India's Paul di Resta.
BBC F1 technical analyst Gary Anderson said: "McLaren look like they could be a bit of a spoiler in here. Their own title chances are pretty remote but they could certainly spoil someone else's. Qualifying is going to be a real thriller."
Vettel, who heads into the race 13 points clear of Alonso in the championship, suffered a set-back when a brake problem left him stranded in the garage for 55 minutes of the hour-long session.
He abandoned his first attempt at a flying lap but on his second was impressively just 0.484secs slower than Hamilton, and in the middle sector of the lap he was faster than anyone.
Hamilton looked immensely strong on the harder 'medium' tyre in the first part of the session - he was fastest by 0.348secs from Button - and more than a second clear of the next car, Grosjean.
Pirelli say the 'soft' tyre, the other choice, should be about 0.5secs a lap faster but as on Friday Hamilton found it difficult to improve, and went only 0.018secs quicker on it.
Button improved a little more to close the gap to his team-mate to 0.290secs.
Alonso, despite his Ferrari carrying a series of aerodynamic upgrades, has looked off the pace on one-off laps all weekend.
He was 1.369secs slower than Hamilton and down in sixth place on the 'medium' tyre and 1.003secs slower - and two places further back - on the 'soft'.
Alonso's pace in the race-simulation runs in second practice on Friday appeared to be strong, but if he starts the race from the middle of the top 10 his hopes will be over almost before it starts.
At Force India, the team have given Di Resta a new chassis for this race after they failed to get to the bottom of handling problems he has been suffering for the last few races.
But although the Scot was 10th fastest, he was still nearly 0.6secs slower than team-mate Hulkenberg.