Slicks were the tyres of choice for the damp track conditions - the lengthy Shanghai circuit drying steadily after heavy morning rain - and Rossi earned his breakthrough victory after a tense race-long battle with Repsol Honda's Dani Pedrosa.

Pedrosa took advantage of some frantic opening laps to make a small break up front, before being caught and passed by Fiat Yamaha rider Rossi, who took the lead for the first time on lap 5 of 22.

But Pedrosa then matched Rossi blow-for-blow and was still just a fraction from the Italian ten laps later, when Rossi made his victory push - pumping out new lap records to finally break the Jerez winner and take a 1.3secs lead with three laps to go.

Pedrosa later explained that there a strong tailwind along the giant back straight - which pushed up the top speeds substantially - had caused his Repsol Honda to over-rev and he was happy to settle for second under the circumstances.

Pedrosa had thus dropped rapidly away from Rossi by the flag, The Doctor taking his first victory since last September's Portuguese Grand Prix - with both fists waving in delight - by a margin of 3.890secs.

Having broken his longest losing steak since his debut 2000 season, a relieved Rossi parked his M1 at the side of the track, took off his helmet and soaked up the moment - before kissing his Yamaha and making his way slowly back to the pits.

MotoGP world champion Casey Stoner also looked set to play a starring role, after qualifying on the front row for the first time this year and holding the lead several times in the early stages, but was forced to watch in frustration as the top two rode away from him.

The Ducati Marlboro star, who hit a staggering 343.2km/h along the back straight, finally finished 12secs behind Pedrosa and 6.5secs ahead of fourth placed Jorge Lorenzo. Stoner later revealed that a softer tyre, in response to the cooler weather conditions, had proved his undoing.

Lorenzo came into the race holding a perfect podium record and the joint world championship lead, but had badly injured his ankles during a huge Friday highside - then stalled on the grid as the formation lap began.

The MotoGP rookie attempted to re-fire his Fiat Yamaha with a bump start, doing little to reduce the pain from his injured ankles, before getting assistance from officials and taking his fourth place on the grid.

The Spaniard, who celebrated his 21st birthday today, looked understandably cautious in the early stages - and had been mercilessly pushed back to eighth by the halfway mark - but retaliated with a combative performance during the last ten laps to pull a comfortable 4.4secs clear of fifth place.

The tailwind on the back straight contributed to a multitude of braking mistakes into the ultra-tight hairpin, with pole sitter Colin Edwards one of the most high profile victims.

The Texan swapped the lead with Stoner during the opening laps but - having been passed by Rossi and Pedrosa - had looked more than capable of holding third, until he ran wide on lap 6.

That dropped the Tech 3 Yamaha rider to seventh, where he eventually finished - in the middle of a close five-man pack - behind Marco Melandri and Nicky Hayden, and ahead of Toni Elias and Loris Capirossi.

Melandri delivered by far his best race of the season, the Italian looking like a man transformed as he charged from 12th on the grid to fifth, shattering his previous best race finish of eleventh and releasing some of the huge pressure on his shoulders after a nightmare start to his Desmosedici career.

Capirossi was the only Rizla Suzuki rider to reach the flag after Chris Vermeulen retired with chain problems, whilst James Toseland endured his toughest MotoGP race yet - crossing the line in twelfth, albeit just a fraction behind fellow rookie Andrea Dovizioso, who faded backwards in the closing stages.

Kawasaki endured a race to forget, John Hopkins managing just 14th after several mistakes whilst trying to force his way forwards from 12th on the grid, while team-mate Anthony West finished in a distant last place - where he had started.

In the world championship standings, Pedrosa has now broken seven points clear of Lorenzo, with Rossi just two points behind his team-mate in third. Stoner remains fourth, but has slipped 25 points - one race win - behind Pedrosa.

Sunday's race was rumoured to be the final Chinese Grand Prix for the foreseeable future - a new round in Hungary, feeding on the huge support for 125cc world champion Gabor Talmacsi, is tipped to replace the Shanghai event from next season.

Chinese Grand Prix:

1. Rossi
2. Pedrosa
3. Stoner
4. Lorenzo
5. Melandri
6. Hayden
7. Edwards
8. Elias
9. Capirossi
10. Nakano
11. Dovizioso
12. Toseland
13. de Puniet
14. Hopkins
15. Guintoli
16. de Angelis
17. West