Honda MotoGP rider Casey Stoner of Australia rides to win the Australian Grand Prix on Phillip Island near Melbourne Oct 16, 2011. Stoner on Sunday clinched the MotoGP world title with a fifth successive Australian Grand Prix victory at the Phillip Island circuit to the delight of the home fans. [Photo/Agencies]

CANBERRA - Honda rider Casey Stoner on Sunday celebrated his 26th birthday by claiming the 2011 Australian Motorcycle Grand Prix (GP) world title at Phillip Island in Melbourne.

The Australian, who turned 26 on Sunday, cruised to victory by 2.21 seconds ahead of Italian Honda rider Marco Simoncelli with his compatriot Andrea Dovizioso.

This it Stoner's fifth straight Australian Grand Prix.

"I don't think I can fit too many more things in this today," Stoner told reporters in Melbourne on Monday.

"It was my birthday, it was my fifth win in a row here, my second world championship, my home grand prix.

"Everything - to win like this is something really special.

"It's been pretty much a dream season for us, everything's gone really well.

"We've had a few ups and downs, but the downs haven't been too far down and the ups have been right up there.

"A big thanks to my team, a big thanks to everyone."

Jorge Lorenzo was the only rider to get within half a second of Stoner during Saturday's qualifying. However, during Sunday's match, Lorenzo was tossed from his bike as he pushed through turn 12 landing heavily and losing part of the ring finger of his left hand. The Spaniard was transported to the medical centre and rushed to Melbourne for plastic surgery.

His withdrawal virtually handed the title to Stoner.

"When I saw Jorge's crash I thought it was just a small crash," Stoner said.

"I thought it might be just a small graze or something like that.

"Then I saw the replay and saw what actually happened and everyone was out there looking for the end of his finger.

"And it sort of made me feel a little bit sick because I'm a racer, I know what it's like to go through these things and you can't really wish them upon anyone."

Australian MotoGP is round 16 of the MotoGP World Championship.