Italian Andrea Dovizioso won the San Marino Grand Prix for Ducati on Sunday while reigning world champion Marc Marquez finished second to increase his MotoGP championship lead to 67 points.

Local favourite Valentino Rossi managed only a distant seventh for Yamaha and lost second place overall to Dovizioso who now has 154 points to Spaniard Marquez's 221 with six races remaining. Rossi has 151.

Ducati's Jorge Lorenzo, who had started on pole position at the Marco Simoncelli circuit on Italy's Adriatic coast, crashed out on the penultimate lap while heading for a Ducati one-two finish.

That lifted Britain's Cal Crutchlow, whose home race at Silverstone last month was cancelled due to heavy rain and drainage problems, to third as the leading non-factory finisher on an LCR-Honda.

"We did everything perfectly," said Dovizioso, who had started in fourth place and was leading after six laps. His winning margin was 2.822 seconds.

"That was the only way to win today because Jorge was very strong and beating Marc was very difficult," added the Italian.

The win was Dovizioso's first at Misano and third of the season as well as his team's third in a row. Lorenzo had won in Austria while his team mate triumphed in the Czech Republic before that.

Lorenzo and Marquez had a lively battle for second place while closing in on Dovizioso but that ended when the polesitter slid out at turn eight.

"It was so difficult," said Marquez, who made the point that Ducati had tested at Misano while Honda had not. "When I saw that Dovi was so strong today my target was to finish second and to lose only five points.

"I'm disappointed that Jorge crashed but we were both pushing a lot because Dovi was there in front."

Australian Jack Miller, who had lined up in second place at the start on a non-factory Pramac Ducati, also crashed out early on while fourth.