Casey Stoner won a fairytale sixth successive Australian Motorcycle Grand Prix on Sunday as Spaniard Jorge Lorenzo clinched the MotoGP world championship.

In his farewell home MotoGP before retiring from the sport, Australian Stoner continued his domination of the Phillip Island event he has made his own since he first won on the track in 2007.

Yamaha rider Lorenzo finished second to secure the world title, with Briton Cal Crutchlow third.

The only other man who could beat Lorenzo for the world championship - Honda rider Dani Pedrosa - crashed out on lap two of the 27-lap race while leading.

Lorenzo has an unassailable lead in the points standings with just one more race remaining this season.

It is Lorenzo's second world title after he won in 2010.

There were suggestions 27-year-old Stoner may not take part in the final race of the season in Spain in a fortnight - perhaps tempted to walk away from the sport on a high he described as one of his career highlights.

But Stoner was adamant he would complete the season before officially farewelling MotoGP, rather than bring forward his retirement.

"I'm here to finish this season, not just finish my home Grand Prix," Stoner said.

"It's not like that for me. I wasn't just planning for this race alone (from his injury). I was planning to come back for as many races as I could before the end of the season.

"It's fantastic, and I can't ask for a better way to end my career in Australia.

"But at the same time, I'm not finishing here. I'm going to Valencia to see if I can get another good result."

Stoner also hosed down any thoughts he may consider a comeback - following five-time world champion Mick Doohan's suggestion the 27-year-old might be in line for a MotoGP return after taking a decent break from the sport.

"I've got no thoughts whatsoever at this time of ever even thinking of coming back," Stoner said.

"I'm very established where I'm going (into retirement). I'm not changing my mind every couple of minutes."

Starting from pole, Honda rider Stoner was beaten off the start line by both Lorenzo and Pedrosa, with Pedrosa taking the lead from his fellow Spaniard late on the opening lap.

But Pedrosa slid out of control while taking a corner less than a minute later.

He returned his Repsol Honda to the pits, and retired from the race.

For Stoner, it was a remarkable result in front of a record Phillip Island MotoGP attendance of more than 53,000.

Once he inherited the lead from the fallen Pedrosa, Stoner built his lead on every lap - Lorenzo perhaps content to do what he needed to in order to wrap up the title.

Stoner eventually beat Lorenzo by more than nine seconds.

Stoner had been dominant all weekend at Phillip Island, having lapped a second quicker than his rivals for most of the practice and qualifying sessions.

More than 122,000 fans attended the three-day event - a 25 per cent increase on last year as spectators flocked to see Stoner in his last MotoGP on Australian soil before his retirement.

AAP