|© AP Photo/Ricardo Mazalan
Jenson Button of McLaren set the fastest time in the final practice for the Brazilian Grand Prix on Saturday, with championship leader Sebastian Vettel second and title challenger Fernando Alonso only eighth.
Button set a lap of 1 minute, 13.188 seconds at Interlagos, just 0.057 in front of Vettel. Mark Webber, also of Red Bull, was third in 1:13.385.
Lewis Hamilton, who dominated the Friday practice sessions ahead of his final race with McLaren, finished fourth in 1:13.389. Alonso only managed a lap of 1:13.691 in his Ferrari.
It was the last time drivers got to practice on the track before qualifying later Saturday.
Vettel needs to finish fourth or better on Sunday to become F1's youngest three-time champion at age 25. Alonso, also seeking his third title, needs at least a podium finish to have any chance of overcoming a 13-point deficit in the standings.
Michael Schumacher, preparing for his final career race before retiring for a second time on Sunday, was 15th fastest with his Mercedes. He just barely avoided a collision with Bruno Senna near the end of his run, having to swerve hard to his left to avoid the Williams car that spun just in front of him.
Alonso's Ferrari teammate, Felipe Massa, the home-crowd favourite, finished tenth. Senna, the only other Brazilian on the grid, was 11th.
The top 12 cars finished within a second of each other at the tricky 2.8-mile track in South America's biggest city.
Hamilton, the winner at the United States GP last week, led the first practice sessions on Saturday, which took place under sunny skies and very high temperatures in Sao Paulo. Vettel was second in both sessions on Saturday, with Alonso finishing fifth.
It remained warm but the sunshine was replaced by clouds for the final practice on Saturday, prompting teams to quickly go out to the track to adapt to the new conditions. Rain was possible for the qualifying session in the afternoon.
Lotus' Kimi Raikkonen, who won his title at Interlagos in 2007, retired less than 15 minutes into the hour-long session with an apparent engine failure. The Finnish driver, trying to secure third place in the standings, also had engine problems in the sessions on Saturday.
Vettel enters the deciding race in a comfortable position to win his third title. He has been dominant recently, finishing on the podium in the last six races and winning four of them.
A fourth-place finish will be enough on Sunday even if Alonso wins the race. And if the Ferrari driver is second, Vettel can clinch the title by crossing the line seventh or better. The German driver holds the tiebreaker because he has more wins than Alonso -- five to three.
Vettel has a chance to become the first driver to win three titles in a row since Schumacher won five straight from 2000-04. The only other driver to win at least three consecutive titles was Juan Manuel Fangio from 1954-57.
Alonso hasn't won a race since the German GP in July, but he finished on the podium in six of the final seven races, including the last four.
It will be the sixth time since 2005 that the F1 season will be decided at the Brazilian GP. Alonso won both of his titles at Interlagos in 2005 and '06.
Red Bull has won the last three races at the track, with Vettel second to teammate Webber last year.
Schumacher, F1's most successful driver, retired for the first time in 2006 after winning seven world titles. He returned in 2010 with Mercedes, but struggled and managed only one podium finish, at the European GP in July.