"I'm very happy because I give more than 100% today," said Rossi. "We've had problems this weekend and even this morning we didn't know if we could fight for the podium.
"I think I did a clever race. I felt confident with the bike, passed Hayden and could go with Loris. At first I was faster in some points and slower in others than Loris, but in the last seven laps he was faster than me.
"Anyway, world champion seven times - last year was a surprise for evrybody, this year all the other teams, bikes and riders tried to beat me but we win another time. A big thank-you to Yamaha and all my guys. Thank you very much," he grinned.
Further back, the only man that could have prevented Rossi celebrating today - Max Biaggi - crossed the line in sixth position, between Melandri and Roberts, while Barros, Hopkins (who never recovered from a tough first lap) and Edwards completed the top ten.
Meanwhile, Shane Byrne finished his first race on a Camel Honda in 14th, while Ruben Xaus and Franco Battaini rounded out the finishers.
Full results to follow...