- Sebastian Vettel finishes third in the Japan Grand Prix to retain F1 world title
- The 24-year-old becomes the youngest-ever back-to-back world champion
- The Red Bull driver is the ninth driver in history to retain his F1 world title
- Nearest challenger Jensen Button wins at Suzuka with Fernando Alonso second
Red Bull driver Sebastian Vettel finished third in Sunday's Japan Grand Prix at Suzuka to become the youngest driver in history to retain his Formula One world championship.
The 24-year-old German went into the race needing just a point to become the ninth man to successfully defend his crown.
And, despite finishing outside the top two for just the second time in 15 races -- ironically the only other occasion was a fourth place in his home German Grand Prix -- Vettel comfortably achieved his target by finishing behind Jenson Button and Fernando Alonso.
Vettel -- who ran down the pit lane to celebrate victory with his mechanics after the race -- told reporters: "I'm so thankful to everyone in the team, pushing hard to build those two cars. It's great to achieve the goal we set ourselves this year already.
"Today's race we weren't as quick on the soft tires and we lost two positions, and it was difficult to get past Fernando," he added.
Only the unlikely scenario of Vettel failing to finish the final five races, with Button winning every one of them, would have seen the British McLaren driver pip his German rival to the title.
And 2009 world champion Button kept up his side of the bargain to win in Japan, finishing 1.1 seconds ahead of the Ferrari of Alonso for his third victory of the year.
"This circuit is very special to all of us, so to get a victory here in front of this Japanese crowd means a lot to us," said Button.
"This gives us a lot of motivation. To see three cars within a few seconds (at the finish) shows how competitive F1 is right now."
Vettel's teammate Mark Webber was fourth for Red Bull with Button's fellow-McLaren driver Lewis Hamilton in fifth position, despite once again clashing with the Ferrari of Felipe Massa.
The clash follows a series of bad-tempered incidents between the pair, with Hamilton running into the back of Massa in the most recent race in Singapore.
Seven-times world champion Michael Schumacher was sixth for Mercedes, while Massa was seventh.
The top 10 was completed by Sergio Perez, Vitali Petrov and Nico Rosberg of Mercedes, who achieved a remarkable placing after starting from second last on the grid.
Vettel has totally dominated the season, winning nine of the 15 races so far, with four second places, a third and a fourth, to follow Alberto Ascari, Juan Manuel Fangio, Jack Brabham, Alain Prost, Ayrton Senna, Schumacher, Mika Hakkinen and Alonso as a double world champion.
It means he has a total of 324 points, a massive 114 clear of second placed Button with four races -- and a maximum 100 points -- still to play for.
Alonso remains third in the standings with 202 points, while Webber stays fourth place on 194.