SAO PAULO -- Rubens Barrichello won the pole position for his hometown Brazilian Grand Prix, emerging from Saturday's chaotic, rainy qualifying as the only Formula One contender in the top 10 on the grid.
Brawn GP teammate and championship leader Jenson Button will start in 14th place and Red Bull's Sebastian Vettel in 15th. Both drivers struggled in a qualifying session which was interrupted twice by red flags and delayed several times because of treacherous track conditions at Interlagos.
Button can clinch the title by finishing third or better in Sunday's race.
The 37-year-old Barrichello finished in 1 minute, 19.576 seconds under extremely wet conditions on the 2.6-mile track, 0.092 seconds ahead of Red Bull's Mark Webber and 0.336 in front of Force India's Adrian Sutil.
"It was a great lap, the maximum that I could achieve from the car," said Barrichello, who had a lighter fuel load than his opponents. "I'm delighted. I am very proud of what we achieved today. I [didn't] think we had the car to be on pole, especially in the wet."
It was Barrichello's second pole at the Brazilian GP, which he is trying to win for the first time in his 17-year F1 career. He is expected to be boosted by about 70,000 fans on Sunday.
"I'm very, very happy," Barrichello said. "It was great to see the people waited to see it. I was expecting people to leave, but I'm very happy they waited."
Defending champion Lewis Hamilton was another who struggled and failed to advance from the first session. He will start 18th in the 20-car grid.
In one of his attempts to improve his time, Hamilton ran off the track and just barely kept control as his car skidded across huge puddles on the infield grass, splashing water everywhere.
"Today was one of the worst qualifying sessions I can remember," Hamilton said.
Qualifying began under heavy rain, which flooded parts of the track and caused near zero visibility.
The session was red-flagged less than five minutes after it started because Ferrari driver Giancarlo Fisichella spun and stopped in the middle of a corner in a dangerous position. Officials waited about 15 minutes to restart the session until conditions improved.
The second session also was delayed for nearly 20 minutes as it continued to rain heavily in South America's biggest city, and it was stopped less than three minutes after it restarted because Force India driver Vitantonio Liuzzi crashed hard after spinning out of control in Turn 1.
It took more than an hour before the cars returned to the track again in slightly better conditions.
Button couldn't find a good setup in the rain and failed to keep up with the pace of Barrichello. The Briton was eliminated in the second qualifying session.
"I couldn't do anything with the car," Button said. "I don't want to be so far back, but at least Vettel is behind me."
Vettel's chances of winning the title took a big hit when he failed to advance from the first qualifying session. His Japanese GP victory two weeks ago kept him in the title hunt, and he needed a good starting position on Sunday to keep his hopes alive. He has to win the second-to-last race of the season and hope Button finishes sixth or worse.
"I confess that I'm frustrated, but tomorrow, when I enter the grid, I'll concentrate on the race," Vettel said. "I'm hoping for really crazy weather tomorrow, varying between dry and wet. That's the only way I'll have a chance in the race."
Vettel moved up a spot on the grid after Force India had to change a gearbox on Liuzzi's car, dropping him from 15th to last place after a five-spot penalty.
The 60-minute morning practice had already been shortened to less than 14 minutes because of downpours.
The Sao Paulo weather has always been a factor at the Brazilian GP. Last year, a downpour with just a few laps to go helped decide the title, which was won by Hamilton thanks to a pass on the last turn of the final lap.
The 29-year-old Button has 85 points, 14 more than Barrichello and 16 more than Vettel. A victory is worth 10 points.
A fifth-place finish will be enough for Button if Barrichello fails to win, and the Briton can even lift the trophy by finishing out of the points as long as his opponents also falter.
If Button is able to clinch the title, he will give Britain back-to-back F1 titles for the first time since Graham Hill won in 1968 and Jackie Stewart in 1969. Lewis Hamilton won with McLaren last year, also at the Brazilian GP.
It would also mark the fifth consecutive time the championship is decided at the Brazilian GP, even though it is not the season-ending race this year. The final race will be in Abu Dhabi on Nov. 1.