A humble Rubens Barrichello was today gracious in defeat after seeing friend and team-mate Jenson Button win the Formula One world championship.

Despite starting from pole and with fellow Brawn GP driver Button down the grid in 14th, Barrichello could only finish eighth in his home race in Brazil, three places behind the Briton.

Button's fifth place was enough to give him the title, opening up an unassailable 15-point lead over Sebastian Vettel, who was fourth at Interlagos, with Barrichello a further two points adrift.

Barrichello was the first man to greet Button when he stepped out of his car, giving him a warm embrace and slap on the back.

"Jenson won it, and he deserved to do it," remarked Barrichello.

"But he won it over the first seven races, and I think the second half of the championship was mine.

"It was a true fight and I fought really hard. I kept going, kept myself alive, and I'm really pleased.

"I'm pleased for Jenson as a friend and as a great champion, and if I didn't win, he should have won it, so well done to him."

Young German Vettel was one of the day's outstanding performers as he started from 15th on the grid before winding up fourth behind race-winning team-mate Mark Webber.

Vettel, who has been tipped as a future world champion, will at least now be able to shave again as he had vowed not to do so until the title was decided one way or the other.

Like Barrichello, the 22-year-old also praised Button as he said: "I think there is a guy at Brawn who is happier than me today.

"I knew Jenson was just ahead or behind me and would score points for the championship, but I didn't really think about it until the last couple of laps.

"Before then you never know what can happen. At one point I was praying for rain and there was the smell of rain, but it didn't come.

"So congratulations to Jenson and Brawn. I think they did the best job this year."