Jenson Button's fifth place in the Brazilian GP ensures he can't be caught with one race to go
Jenson Button and his Brawn GP team were crowned Formula One champions in the Brazilian Grand Prix won by Australian Mark Webber of the Red Bull team.
Button finished fifth to become Britain's 10th world champion.
Brawn teammate Rubens Barrichello suffered a late puncture and crossed the line eighth after starting on pole position.
Button was ecstatic after a rain-hit qualifying session left him starting 14th.
"Oh what a race. I am world champion, I am world champion. It's been such an interesting season," he said.
"It is really amazing. Today was such an awesome race and I am world champion. I never expected to be world champion in Formula One.
Button, winner of six of the first seven races, now has 89 points to Sebastian Vettel's 74 and Barrichello's 72.
Brawn, who had needed only a point to be sure of the constructors' championship, become the first team to take the crown in their first full season.
1 Mark Webber RBR-Renault
2 Robert Kubica BMW Sauber
3 Lewis Hamilton McLaren-Mercedes
4 Sebastian Vettel RBR-Renault
5 Jenson Button Brawn-Mercedes
6 Kimi Räikkönen Ferrari
7 Sebastien Buemi STR-Ferrari
8 Rubens Barrichello Brawn-Mercedes
9 Kamui Kobayashi Toyota
10 Giancarlo Fisichella Ferrari
11 Vitantonio Liuzzi Force India-Mercedes
12 Heikki Kovalainen McLaren-Mercedes
13 Romain Grosjean Renault
14 Jaime Alguersuari STR-Ferrari
Ret Kazuki Nakajima Williams-Toyota
Ret Nico Rosberg Williams-Toyota
Ret Nick Heidfeld BMW Sauber
Ret Adrian Sutil Force India-Mercedes
Ret Jarno Trulli Toyota
Ret Fernando Alonso Renault
Kovalainen originally finished ninth, but had 25s added to his race time due to an unsafe pit stop release