Bettini managed to edge Zabel to the finish line for his first title

Olympic champion Bettini, who rides for Quick Step, moved past German veteran Zabel in the final 100m of a two-man sprint to the finish line.

The 32-year-old completed the 265.2km route in six hours 15.36 seconds for his first world road race title.

Zabel, 37, had to settle for second with Spain's Alejandro Valverde third, more than two bike lengths behind.

"I dreamed about becoming world champion," said Zabel.

"It is awful when you still lead with 50 meters to go. But silver gives me joy, too."

Bettini said that he had been confident before the race but did not expect such a drawn-out finish.

"It was the longest finish I ever raced," said Bettini. "We knew we had great potential.

"The course was very fast but when I attacked I knew it would be hard to stay clear on the descent.

"The team rode to set me up for the sprint but then when I saw the other leading riders go fast into one of the final corners I dived after them.

"I hit my shoulder on the barriers and I was scared of crashing but knew I had to risk it because the move was decisive.

"It's ironic because we raced hard all day and then we went clear in the final corner. One corner decided the race."

Bettini gave conflicting signals over his plans now he is world champion.

"It was a fantastic win and has enabled me to achieve a dream. After this win my career could finish here.

"Now I have won all the classics except the Tour of Flanders but there's time for that."

But it was disappointment for Belgium's Tom Boonen, who failed to retain his 2005 title as he finished ninth.

In a tense finale, Bettini made the perfect play by jumping on the wheel of Zabel when the German broke away with 200m left after a four-man split in the bunch.

Valverde failed to see the move until too late but finished ahead of compatriot Samuel Sanchez and picked up a third medal from the championships, having been runner-up last year and in 2003.

Australian Robbie McEwen was fifth with compatriot Stuart O'Grady sixth.

Men's road race results at the World Championships on Sunday: