Valentino Rossi has scored one of his greatest MotoGP victories after a stunning bar-to-bar battle with Casey Stoner during Sunday's US Grand Prix, which ended in favour of the Italian when Stoner dropped his Ducati with eight laps to go.

Acutely aware of Stoner's awesome practice pace, which saw the Ducati rider lead every track session by at least 0.447secs, Rossi was determined not to let Stoner break away in the race - and made his intentions clear before the end of the first of 32 laps.

Stoner took the lead from pole but Rossi - who joked on Saturday that he needed a 30-second head start to beat Stoner, and that 'the only way to stop Stoner was to shoot him' - gave the young Australian a taste of what to expect by diving inside the Ducati rider on the entry to the corkscrew.

But the real action between the pair began on lap four, when Stoner retook the lead from Rossi into turn one, only for Rossi to fling his Fiat Yamaha back underneath into Turn Five.

Stoner was back ahead on the run up to the corkscrew, when Rossi again lunged inside - this time running over the dirt as he dived downhill, pushing both riders wide on the exit!

If Stoner had any doubts about how determined Rossi was to stay ahead of him, they were eradicated on the following lap when Stoner once again took the lead along the home straight - and again Rossi block passed him straight back into Turn Five.

Stoner's next assault came on lap 14, when he ran around the outside of Rossi through turn one - but outbraked himself into the double apex, forcing him to tip-toe back onto the racing line.

If Rossi had been trying to rattle Stoner, it looked to be working.

Nevertheless, Stoner still possessed the better ultimate pace and had re-caught Rossi within two laps. The deciding moment of the race then occurred when Stoner's rear wheel bobbled under braking for the final turn on lap 24.

The Australian came close to clipping Rossi before running wide and dropping his Desmosedici when the front wheel dug in to the deep gravel.