Casey Stoner rated himself lucky, but there was no denying his skill as he won a wet and dangerous British MotoGP to leapfrog defending champion Jorge Lorenzo at the top of the world championship standings.

Stoner, who started on pole, conquered a drenched, slippery Silverstone circuit to clinch a fourth victory in six rounds, becoming the first Honda rider to win three successive MotoGP races since Valentino Rossi in 2003.

The 2007 world champion moved 18 points ahead of Lorenzo, who was in second place behind Stoner when he crashed out on the eighth lap – seconds after teammate Ben Spies also fell.

“It was really tough conditions,” said Stoner, who was starting his 150th grand prix in all categories and was quickest in practice on Friday and Saturday.

“Anything could have happened. We were quite lucky in this one that I stayed up and that Jorge had a crash.”

Honda’s Andrea Dovizioso was second, allowing the Italian to trim the gap to Lorenzo in the overall standings to 15 points, while Yamaha’s Colin Edwards (US) was third on his return from a broken collarbone.

Heavy rain, which left surface water across much of the 5.9km circuit, accounted for Honda’s Marco Simoncelli on the 10th lap, the Italian rider skidding out as he braked approaching a corner while running third.

Stoner was overtaken by Lorenzo by the first corner, but retook the lead on the second lap, despite having his vision impaired by water in his visor, and was rarely threatened after that.

“At the beginning, we didn’t get a great start. But the bike felt good, and I waited for the tyres to get up to temperature,” Stoner said.

“In the first lap, I had water in my visor so, for the first five or six laps, I couldn’t really see properly. I couldn’t see any puddles. But finally the water went away and I was able to do the lap times I wanted and open up a gap.

“For the last seven laps, it was torture. My hand was freezing and I couldn’t understand what brake pressure I had.”

After Lorenzo crashed out, Dovizioso and Simoncelli were engaged in a close battle for second, but the latter’s error gave his compatriot some breathing space. Dovizioso finished more than 15 seconds behind Stoner.

In the Moto2 class, Germany’s Stefan Bradl was a comfortable winner aboard a Kalex to extend his lead in the overall standings to 62 points from Simone Corsi, who could only finish 10th.

It was Bradl’s fourth victory in six races.

Aprilia rider Jonas Folger of Germany won the 125cc race, pipping Frenchman Johann Zarco.