MotoGP world champion Valentino Rossi [Images] made light of appalling conditions to win a crash-strewn British Grand Prix on Sunday.

The Italian Yamaha rider was the undisputed rainmaster, totally dominant in taking his seventh victory in nine races to move 104 points clear of compatriot Marco Melandri in the championship.

"That was one of the most difficult races of my career," the six-times World Champion said. "It was very cold, very slippery and very difficult to see the track.

"Today was not like riding a motorcycle. It was like driving a boat."

The 75,651 drenched fans at Donington Park watched Spaniard Sete Gibernau seize the early lead, only to crash out after three of 29 laps.

Next up was Suzuki's John Hopkins, the American leading for two laps before a slide sent him dropping back from the leading group. He then fell, one of 11 victims of the treacherous soaking surface.

The battle was then between four riders, with Honda's Brazilian veteran Alex Barros leading from lap seven to 21 in his 250th grand prix.

Kenny Roberts Junior, on a Suzuki, and fellow-American Colin Edwards for Yamaha, were up close but Rossi was with them and biding his time.

The champion made his move with eight laps to go, taking the lead and immediately opening up a comfortable gap of more than eight seconds after five more laps.

By the finish he could afford to stand on the footpegs and give a mock violin recital as he crossed the line, still 3.619 seconds clear.

WAITING GAME

"Today was a very long race. I remember my first win in the top class, on a 500cc bike in 2000, at this track. Today it was worse -- there was a lot of water on the track, no grip, and it was very cold," said Rossi.

"At the start I had too much wheelspin. Then I saw a lot of people crash in front of me. I also almost crashed, so I decided to wait.

"Then when I tried to pass Kenny (Roberts) I went wide at the chicane. I could catch up again quite easily, so then I understood I could go faster," he said.

"When I was second behind Barros, I waited for three laps to get the rhythm, then I passed and gave my best for the next few laps," said Rossi.

Roberts was also waiting his chance, attacking Barros on the final lap to take second, the 2000 World Champion's first top-three finish since 2002.

"It's been a long time. For me it was the best possible result. I tried to run my own race, and be there at the end, but Valentino had the courage and the confidence, and I didn't have anything to match him."

Barros, winner of the Portuguese GP, had a similar story.

"When Valentino overtook me I couldn't follow his pace. I had a big problem with my front tyre, but even so he was very fast. Then I had a great race with Kenny, and he won," he said.

In the 250cc category, France's [Images] Randy de Puniet took his first win of the season on an Aprilia while championship leader Daniel Pedrosa of Spain was third. Pedrosa leads Australian Casey Stoner, second on Sunday, by 34 points.

Spaniard Julian Simon won the 125cc race, his first grand prix victory. Hungarian Gabor Talmacsi and Italian Mattia Pasini both retired but lead the championship with 100 points each. Switzerland's [Images] Thomas Luthi is one behind.