VALENCIA, Spain - Valentino Rossi remained in philosophical mood despite seeing a sixth successive premier class world title slip from his grasp after he made two uncharacteristic errors in the Valencia MotoGP on Sunday.

Yamaha MotoGP rider Valentino Rossi crashes during the Spanish Grand Prix at the Cheste racetrack near Valencia October 29, 2006. American Nicky Hayden took advantage of a rare error by five-times champion Rossi to claim his first MotoGP world title in a dramatic race in the season-ending grand prix in Valencia on Sunday. [Reuters]

The 27-year-old Italian went into the final race with an eight-point advantage over title rival Nicky Hayden, but a poor start from pole position and an error that resulted in him sliding off the track in the early laps ended his chances and gave the American the championship.

"It was a difficult race and we had some problems," said Rossi who crossed the line in 13th place while Hayden came third to win the title by a five-point margin.

"I made a mistake off the start and another on the slide. I don't understand why I slid but when you crash it is always a mistake."

Rossi had been 51 points adrift of Hayden in the championship standings at the end of July, but the Yamaha rider staged a remarkable comeback in the final third of the season to head into the final race at the top of the standings.

"It's a big emotion this year, positive and negative," he said. "We were able to gain 51 points from (the Czech Grand Prix in) Brno to arrive in front to the last race but unfortunately we lost.

"We did a lot of incredible victories but in life it is always possible to lose."

Rossi was sporting in defeat and heaped praise on Hayden who was a former team mate of his at Honda in the 2003 season.

"Great congratulations to Nicky, he did a great job. He's a good guy and a great rider. He won, he's the best and I'm very happy for him.

"He's a great fighter, he's always very fair and I've got a great relationship with him, his father and all his family."