Piloting a four-stroke Honda RC211V that he'd taken to 315 kph in dry practice, Valentino Rossi won Sunday's rain-soaked Japan MotoGP at the Suzuka circuit in Mie Prefecture.

Speaking after the traditional champagne shower from the winner's podium, the 23-year-old Italian maestro said, "I am happy whenever I win a race, but today's was special because the conditions were very difficult and also this race was important for Honda.

"This morning's warm-up was my first wet-weather outing with the RC211V, and I was learning during the race.