(CNN) -- Rubens Barrichello boosted his chances of overhauling Brawn teammate Jenson Button and winning his first world title by claiming pole position for his home Brazilian Grand Prix in treacherous conditions on Saturday.
Home hero Rubens Barrichello last started a race from pole when he was driving for Ferrari in 2004.
The 37-year-old will start a race from the front for the first time in five years on Sunday after championship leader Button -- who he trails by 14 points with two races left -- failed to make the final session of qualifying as rain drenched the Interlagos circuit in Sao Paulo.
Button had earlier been encouraged as his other main rival, Red Bull's Sebastian Vettel, failed to make it past the first stage of qualifying.
However, the British driver will start 14th on the grid, just two places ahead of the German, after making a tactical error in sticking with extreme wet tires in the second session.
"The start of the session we had way too much understeer and I couldn't do anything with it, and then on lap three the rear started going away," Button said.
"We made a mistake not putting intermediate tires on at the end but it's a collective decision, it's a team effort."
Barrichello has never won in 16 races in his home city, with third his best finish, but has the perfect chance to remedy that and upstage Button, who has led all season.
He clocked a time of one minute 19.576 seconds to inspire chants of "Rubinho, Rubinho" from the delighted crowd, heading off Red Bull's Mark Webber (1:19.668) and Force India's Adrian Sutil (1:19.912).
"After so many years in Formula One, now my 17th, I've never got out of the car to go pee twice in the middle of qualifying," Barrichello, on pole for the 14th time in his career, said of the day's several delays for rain.
"I love these conditions and I'm really happy for those fans who stayed behind to see all this. "We never knew what was going to happen, whether to employ plan A, B, C or D. The conditions were so variable but I'm so happy.
"We may have less fuel than the guys behind us, but it's better to be at the front than in the middle of the pack."
Toyota's Jarno Trulli was fourth ahead of Ferrari's Kimi Raikkonen, whose teammate Giancarlo Fisichella missed qualifying after spinning out in practice and will start from last.
Toro Rosso's Sebastien Buemi claimed sixth ahead of Williams' Nico Rosberg, with BMW Sauber's Robert Kubica eighth.
Kazuki Nakajima was ninth in the second Williams, while two-time world champion Fernando Alonso was 10th ahead of his second-to-last race for Renault before replacing Raikkonen at Ferrari.
World champion Lewis Hamilton will start from 18th place, one behind McLaren teammate Heikki Kovalainen, as both failed to make it past the first hurdle.
"The conditions were awful, but, wow, our car was terrible. Pretty poor performance from us," Hamilton said.
"We couldn't even go flat-out on the straights. That's how bad it was. We didn't have a wet weather set-up, which probably contributed to it."
Force India's Vitantonio Liuzzi was 15th, but lucky to escape without injury after crashing into the pit wall.