Suzuka: Red Bull's Sebastian Vettel became Formula One's youngest double world champion on Sunday after finishing third in a Japanese Grand Prix won by McLaren rival Jenson Button.
The boyish 24-year-old German, who had started from pole position for the 12th time this season, had needed only a point at Suzuka to clinch his second successive crown with four races to spare.
Ferrari's Fernando Alonso, the previous youngest double world champion when he won for Renault aged 25 in 2006, was a close second on a beautiful sunlit afternoon at the Honda-owned circuit.
"Thank you so much, every single one," said Vettel, his voice trembling with emotion as he choked back the tears behind his visor, over the team radio after being told he was the 2011 world champion.
"We took nothing for granted and we did it."
Vettel, only the ninth driver to take back-to-back championships, had vowed to retain the title in style and his aggression and determination was evident from the start as he cut across Button and forced the Briton onto the grass.
"He's got to get a penalty for that," Button shouted over the radio but stewards, who included Australia's 1980 champion Alan Jones, decided to take no further action after reviewing the incident.
Vettel pulled away initially at a second a lap but 2009 champion Button reined him in and took the lead at his second pitstop when he emerged just ahead of the German in a race dictated by tyre wear.More on Formula One
A safety car incident triggered by another coming together between McLaren's Lewis Hamilton and Ferrari's Felipe Massa, as well as a contact between Red Bull's Mark Webber and Mercedes' Michael Schumacher, bunched up the field for three laps while marshals retrieved debris.
Button kept his lead and took the chequered flag for what he considers a second home race, thanks to his Japanese girlfriend and long-standing passion for the country, just 1.1 seconds over Alonso.
The Spaniard had threatened to take the win but Button had just enough in his tyres to keep him at bay. Vettel was only 0.8 further back.
The win cut Vettel's overall lead over the Briton to 114 points, an insurmountable advantage with a total of 100 left to be won.
Hamilton, who has had numerous calls to the authorities this season, finished fifth after stewards took no further action for the incident with Massa that ripped off the Ferrari's front wing endplate.
Australian Mark Webber was fourth for Red Bull.
Schumacher, who briefly led the race during the pitstops, was sixth and Massa seventh.