Casey Stoner is the new MotoGP world champion after winning his fifth successive Australian Motorcycle Grand Prix at Phillip Island today.



The Australian, who turned 26 today, cruised to victory by 2.21 seconds from Italian Honda rider Marco Simoncelli with his compatriot, Andrea Dovizioso, on another Honda in third.



Stoner was virtually handed his second world title after his triumph on a Ducati in 2007 when his only rival, Yamaha's Jorge Lorenzo, was ruled out after crashing during the warm-up.



Lorenzo was tossed from his bike as he pushed through turn 12 and landed heavily and lost part of the ring finger of his left hand.



The Spaniard was transported to the medical centre and rushed to Melbourne for plastic surgery.



Marshalls found Lorenzo's left glove but it is understood the impact left no clean cut, meaning the tip of the finger could not be re-attached.



Stoner had pole position on the grid as he chased his fifth-straight Australian race and was left with little to do but finish sixth or better to take out the championship, with rounds in Malaysia and Valencia remaining.



He blasted away from pole position and by the end of of lap one of the 27-lap race had pulled out a gap of one second over Simoncelli.



Stoner was quickly out of sight of the pack, riding a lone race at the front and increasing his lead by almost a second each lap.



But he gradually eased off the throttle as a brief shower fell and crossed the line for a comfortable win.



Ducati's seven-time world champion, Valentino Rossi, had his miserable weekend culminated by a crash on lap 13, which ended his race.



Taree rider Damian Cudlin, a replacement for the injured Ducati racer Hector Barbera, took a bad spill during yesterday's final practice session and was unable to take his place on the grid.



AAP