Casey Stoner is on the brink of clinching the 2007 world championship after handing Ducati its first MotoGP victory on home soil with a dominant performance at Misano - while Valentino Rossi failed to finish.

Stoner used his fourth pole position in a row to take an early lead, while second on the grid Rossi dropped to third behind John Hopkins. Just behind them, Kawasaki's Randy de Puniet collided with Dani Pedrosa at turn two - bringing them both down and forcing Pedrosa's Repsol Honda team-mate Nicky Hayden, who had made a poor start from the front row, into the gravel.

Chris Vermeulen, fastest in morning warm-up, wasted no time in passing Rossi for third early on in the first lap - but greater drama was to follow when the Italian suffered a shock engine failure on lap five, silencing the 57,321 fans. Rossi had been using the new M1 engine, featuring pneumatic valves, for the first time in a race.

Rossi, whose home town of Tavullia is just ten miles from Misano, began the event 60 points behind Stoner and The Doctor's second DNF of the season - after an accident at the Sachsenring - meant not only the end of his home victory streak, having won the last six Italian Grands Prix at Mugello, but also the end of his realistic 2007 world championship hopes.

With just five races and 125 points still up for grabs, Stoner is now 85 points clear of Rossi and is it theoretically possible for the 21-year-old to wrap up his and Ducati's first MotoGP crown next time out in Portugal, although the following Japanese Grand prix is most likely.

As last time out at Brno, and unfortunately for MotoGP's worldwide TV viewers, Stoner led from start to finish - and again a Suzuki rider provided his nearest opposition, this time in the form of fellow Australian Chris Vermeulen, who overtook team-mate Hopkins shortly after Rossi's withdraw.

The Le Mans winner then closed to within one second of Stoner, but by the halfway stage Casey had pulled 1.8secs ahead and Stoner eventually won his eighth race of the season by a margin of 4.851secs... then ran out of fuel on the slowdown lap!

Hopkins made it two GSV-Rs on the podium for the first time since the formation of the MotoGP class, and also became the first Suzuki rider to take back-to-back podiums since Kenny Roberts in 2000.

Hopper finished a lonely 11 seconds behind Vermeulen and seven seconds ahead of fourth placed Marco Melandri - who again defied his injuries to charge from 12th on the grid and beat fellow Italian Loris Capirossi, whose factory Ducati ride Marco will take next season, by two seconds.

Top Michelin rider Carlos Checa, a healing Toni Elias, the newly resigned Anthony West, Rossi's team-mate Colin Edwards and Konica Minolta's Shinya Nakano completed the top ten, while Hayden only reached 13th at the chequered flag.

San Marino Grand Prix:

1. Stoner
2. Vermeulen
3. Hopkins
4. Melandri
5. Capirossi
6. Checa
7. Elias
8. West
9. Edwards
10. Nakano
11. Hofmann
12. Guintoli
13. Hayden
14. Tamada
15. Roberts