Italy's Valentino Rossi held off a determined challenge by defending champion Marc Marquez to win the Dutch TT in Assen and extend his lead in the MotoGP world championship.

The nine-time champion, who regained the lead with three laps to go having been passed by the Spaniard seven from the finish, was clipped by his rival heading into the final chicane, and although he was briefly forced on to the gravel, he regained his composure to finish 1.24 seconds ahead.

Rossi's third win of the season stretched his lead at the top of the standing to ten points from Jorge Lorenzo, who finished nearly 15 seconds adrift in third after a poor performance in Friday's qualifying cost him.

Ducati's Andrea Iannone edged ahead of the pack to finish fourth, with the gap between him and eighth-placed Daniel Pedrosa just over five seconds.

Within that group Britain's Cal Critchlow just beat compatriot Bradley Smith for sixth.

There were a number of crashes, with Hector Barbera coming off worst in his encounter with Jack Miller at the chicane on lap one as he was taken from the track on a stretcher, although he was conscious and appeared to be unharmed.

Ireland's Eugene Laverty retired from the race after 11 laps.