Lewis Hamilton of McLaren was fourth and championship leader Fernando Alonso of Ferrari fifth.

Hulkenberg stunned the field with a fastest lap of 1 minute, 14.470 seconds at the 4.3-kilometer (2.6-mile) Interlagos track, while Vettel clocked 1:15.519 and Webber set a time of 1:15.637.

It was the first pole for Hulkenberg, who took advantage of a damp track in the session that set the field for a race that could decide the Formula One championship.

Five drivers are still in contention with two races to go, but only Alonso can clinch the championship in Brazil.

Webber, Hamilton, Vettel and Jenson Button are trying to extend the title race into the season-finale on Nov. 14 in Abu Dhabi.

Alonso has 231 points, 11 more than Webber and 21 more than Hamilton. Vettel is 25 points back and Button is 42 behind. The win is worth 25 points.

It rained overnight and all morning long in Sao Paulo and the final practice session took place under very wet conditions. It stopped raining before qualifying, however, and drivers were able to run on intermediate tires on a damp track. Everyone put on slicks in the final minutes and Hulkenberg was the one who made the most of his runs.

The Red Bulls had set the pace in the first day of practices on Friday, with Vettel leading Webber in both sessions in dry conditions. Their rivals had been hoping for rain on Saturday to try to reduce the Red Bull's advantage and even the field going into qualifying and the race on Sunday.

Although Red Bull has won the pole 14 times in 18 races this season - nine for Vettel and five for Webber - the team has not been able to translate its dominance into nearly as many race wins, thanks mostly to driver mistakes and mechanical failures. Vettel has won only three times this season and Webber four.

Rain caused havoc in last year's qualifying session at Interlagos, sending top contenders to the back of the grid.

Button had to start in 14th place, with Vettel in 15th and Hamilton in 17th.

To win his third F1 title in Brazil, Alonso needs to win Sunday's race and hope Webber finishes fifth or worse. The Spaniard can also secure the title if he finishes second and Webber places eighth or worse, Hamilton is fourth or worse and Vettel second or worse.

The drivers' championship has been decided at the Brazilian GP in the last five years. Button won it with Brawn GP in 2009, as did Hamilton with McLaren in 2008 and Kimi Raikkonen with Ferrari in 2007.

It was at Interlagos that Alonso won his first two titles, in 2005 and '06, with Renault. He is debuting with Ferrari after a disappointing year with McLaren in 2007 and two seasons with Renault before replacing Kimi Raikkonen in the Italian team.

Force India's Adrian Sutil and Toro Rosso's Sebastien Buemi automatically lost five grid position after being penalized for causing collisions at the Korean GP two weeks ago.