Briton Jenson Button has been crowned Formula One drivers world champion after finishing fifth in an incident-filled Brazilian Grand Prix won by Australian Mark Webber.
Button, who has led the championship all season after winning the opening Australian Grand Prix in March, had started 14th on the grid, but drove with courage and determination to achieve his goal and send the Brawn GP team into wild celebration.
His success ensured also that the Brawn team, created out of the ashes of the defunct Honda team last winter, also clinched the constructors' world championship.
Button's great success came in his 169th Grand Prix and at the end of his ninth season in Formula One, a year when he won six of the opening seven races and then struggled to recapture that form.
Webber, in a Red Bull, won comfortably ahead of Pole Robert Kubica in a BMW Sauber and third-placed outgoing drivers' champion Briton Lewis Hamilton in a McLaren Mercedes.
German Sebastian Vettel, in the second Red Bull, was fourth ahead of Button with Finn Kimi Raikkonen sixth for Ferrari.
Swiss Sebastien Buemi of Toro Rosso was seventh and the luckless local hero Brazilian veteran Rubens Barrichello, in the second Brawn, eighth after starting from pole position.
Webber, who started alongside Barrichello at the front of the grid, led the race from the early stages and was never headed as he cruised to just the second grand prix victory of his career.