The Italian's Yamaha mate Jorge Lorenzo was second, just over three seconds behind the winner, and Toni Elias of Spain finished third on his Ducati.

Ducati's Stoner, who started in pole position, was alone at the front when he slid off the track into the gravel and pulled out of the race. He had already crashed out of the Czech MotoGP in Brno two weeks ago.

The Italian rider capitalised on Stoner's exit, taking the lead and pulling away to equal Giacomo Agostini's record of 68 premier class victories.

Rossi, the winner of seven world championships, now leads the standings by 75 points, ahead of Stoner.

"Agostini helped me to win", Rossi told Mediaset television cheerfully. "Stoner was going very fast but I had a good feeling with my bike, then I saw him slipping," the Italian added.

There are five races left in the season with the next Grand Prix at Indianapolis on Sept. 14. Race winners gain 25 points.

Honda's Nicky Hayden of the United States missed his second race in a row due to his foot injury, after qualifying 16th on Saturday.

Spain's Honda rider Dani Pedrosa finished fourth to close the gap between himself and second-placed Stoner to two points. Australian Chris Vermeulen, on a Suzuki, was fifth.

Honda's Alex De Angelis of San Marino and his French team mate Randy De Puniet fell off their bikes and did not finish the race.

Rossi's home town of Tavullia is near the Misano track so he was roared on by thousands of fans, including former Argentine soccer great Diego Maradona.

In the 250cc class, Spain's Alvaro Bautista won the race on his Aprilia from the third row, followed by Honda's Yuri Takahashi of Japan. Spain's Hector Barbera was third.

Italy's Marco Simoncelli, on a Gilera, finished sixth but kept his overall 250cc lead by 26 points from Finland's Mika Kallio on a KTM.

Hungary's world champion Gabor Talmacsi took the 125cc victory to move up a place to third in the overall standings. Frenchman Mike di Meglio, kept the overall lead despite falling from his Derbi.

Reuters