The Ducati rider finished ahead of American Colin Edwards, who started from pole position on his Yamaha, with Australian Chris Vermeulen of Suzuki third on a circuit made slippery following earlier rain at Donington Park.

Stoner added to his wins in Qatar, Turkey, China and Catalunya two weeks ago to extend his lead on Italian Valentino Rossi in the world standings after the Yamaha rider crossed in fourth position.

Last year's winner Dani Pedrosa of Spain finished eighth despite leading for the first four laps before Edwards took the lead which he held until mid-race when he took a bend too wide and was overtaken by Stoner.

Earlier Italian Honda rider Andrea Dovizioso scorched to victory under the rain in the 250cc category ahead of San Marino's Alex De Angelis and Hiroshi Aoyama of Japan.