Alonso became the youngest driver to seal back-to-back titles

He finished second behind Felipe Massa to seal back-to-back world titles, 13 points clear of Michael Schumacher.

"It's been a great weekend," he said. We did it and now I am going to have the biggest party of my life."

"And I have to say that it means more to be the double champion now and win these titles while Michael Schumacher was racing than any other time."

Report: BBC Five Live's David Croft

Alonso joined a list of racing legends on Sunday in becoming only the eighth driver in Formula One history to win successive titles and the youngest at 25.

The Spaniard headed into Sunday's title decider, needing just one point to be certain of his retaining his world crown.

It is my last race for Renault and I am so glad we won both titles - that was the important thing Fernando Alonso

And he did not disappoint, driving a steady, flawless race at Interlagos as title rival Schumacher ended his glorious 16-year career at the pinnacle of motorsport with fourth after fighting back from an early puncture.

Alonso on his own did enough for Renault to win the constructors' championship from Ferrari, but team-mate Giancarlo Fisichella's sixth place left the final margin at five points.

"It was a very good race for us," added Alonso, who joins McLaren next season. "I only needed a point to become champion, and I was ready to help the team become constructors' championships.

"It's a great feeling. It is my last race for them and I am so glad we won both titles - that was the important thing.

"Felipe and Ferrari were too quick for us in the race, but we did the job."

On Schumacher who had clawed back a 25-point deficit in June to challenge for the title, Alonso was full of praise for his retiring rival.

"It's been very close," the Renault driver said. "It's been good to fight with him."

"If he is on the track, it is tougher and it is of more value.

"It is an honour to have won the final two championships of his career. He is retiring as the man with all the records, and it has been a big pressure to race against him - and a big privilege as well."