Suzuki's Chris Vermeulen enjoyed his maiden MotoGP win in a rain-swept French Grand Prix at Le Mans.
Vermeulen's early switch from slick tyres proved to be decisive
The Australian was followed home by Marco Melandri while Casey Stoner's third place increased his lead over Valentino Rossi in the title race.
Rossi was sixth while world champion Nicky Hayden was lying fourth with two laps to go but then crashed out.
Vermeulen switched to a bike set up for the rain a lap earlier than most of his rivals, which proved decisive.
Seven riders did not finish the race because of the treacherous conditions with polesitter Colin Edwards the last of the 12 riders to finish.
Stoner now leads Rossi in the overall standings by 21 points.
With drizzle turning into heavier rain 20 laps from the finish line, front-runners Sylvain Guintoli, Randy de Puniet and Toni Elias all crashed out.
And Vermeulen said: "When I saw all those riders on the ground I just tried to keep it together.
"(Deciding) when to come to the pits and change tyres was the hardest part. I must admit I followed my instincts, I did not really think.
"Then I saw my lead increase until Marco came closer but I realised he was at the limit."
In the 250cc class, Spaniard Jorge Lorenzo rode his Aprilia to his fourth victory from five races this season to extend his world championship lead to 32 points.
Lorenzo has been in fine form this season with four wins to his name
Lorenzo, whose only defeat this year came in Turkey by Italian rival Andrea Dovizioso, took a decisive lead with six laps to go and beat the Honda rider by 0.156 seconds.
"All the team did a good job on the bike on Friday night. I am very happy because it was a very difficult race," Lorenzo said.
"Andrea has been a very competitive rival, it's always very difficult to beat him."
Bradley Smith finished third in the 125cc class to become the first British rider to finish on the podium since 1989.
The 16-year-old from Oxfordshire had his best result in only his second full season of GP racing to move up to eighth in the world championship standings.
The Repsol Honda rider, who had started the race in second on the grid, was beaten by Sergio Gadea's Bancajar Aspar Aprilia and the Valsir Seedorf Derbi of Lukas Pesek, who stretched his lead in the world championship to nine points.
Smith said: "It's a first time on the podium (in GPs) for me and I've really enjoyed it.
"The race was really hard and I had to push really hard at the beginning. The team have built me up to this podium and it's a big 'thank you' to them."