It has been just a few days since Valentino Rossi crossed the line at Motegi to cement his sixth MotoGP world title in the best way possible, but already he is having to get his head down again for the next race in Australia.

With no chance to nurse the hangover from his triumph in Japan, the ever-committed Rossi heads south with an agenda to return to winning ways around a circuit he was once able to call his own.

With an unprecedented five wins stretching between 2001 and 2005, the past two seasons have seen Rossi off the top step of the rostrum, but with the pressure off, he is determined to rectify that fact over the weekend.

One of the most important races on the calendar historically, Phillip Island has hosted the Australian Grand Prix on 14 occasions and is generally regarded as a favourite amongst the riders on the grid.

Defined by its steep gradients and sweeping high-speed layout, Phillip Island's is also notable for proximity to the coast due to its location on an island (hence its name), while the late season slot of the Australian Grand Prix means weather is generally cool and unpredictable.

Nonetheless, despite its unusual position and often unfavourable weather, Phillip Island draws out the fans in their thousands, most recently to cheer on their hero Casey Stoner.

Although the celebrations may be a more muted than usual after seeing Stoner relinquish his title status to his arch-rival, the Ducati rider will be more determined than ever to return to winning ways following something of a barren spell.

The Aussie led home a Ducati 1-2 over team-mate Loris Capirossi last year, but he has his work cut out to prevent a confident Rossi from re-establishing his authority around this circuit.

Their closest challengers are likely to be Spanish duo Dani Pedrosa and Jorge Lorenzo, who both showed flashes of brilliance in Motegi. Lorenzo qualified on pole position, and while he would eventually fade to fourth, it is the latest fillip in an obvious return to confidence for the Yamaha rider.

Pedrosa, meanwhile, is embarking on a steady trajectory back to the front of the field as he continues to adapt to the pneumatic-valve, Bridgestone-shod Repsol Honda. Finishing a fine third at Honda's home round, he remains only 19 points adrift of the runners-up spot, even if it may take another Stoner retirement for him to snatch the position off him.

The battle for fifth in the standings rages on as Andrea Dovizioso stays firm with a gap of 18 points over Colin Edwards. However, he is being chased by three riders now as Nicky Hayden has joined the chasing group, his fifth place in Japan latching him onto the back of Chris Vermeulen. Just three points separate sixth to eighth, although you wouldn't bet against Hayden to leap ahead of his rivals by the end of the weekend if he can maintain his strong form.

Things are equally tight just behind as Loris Capirossi, Shinya Nakano, James Toseland and Toni Elias dispute who will or won't feature inside the top ten by the end of the season.

Currently, Capirossi is in charge in ninth after a solid ride to sixth on the Suzuki at Motegi, although he is just a single point up on Nakano, who clings onto a top ten spot after an improved outing at his home round.

Five and nine points further back are Toseland and Elias. For Toseland, Phillip Island marks the start of a run of circuits he has visited before, a factor that gives him much needed confidence for the weekend. A good result is necessary though as he seeks to prove it is his lack of knowledge around new circuits that has contributed to his inconsistent form this year.

Kawasaki enjoyed a good performance at Phillip Island last year in the hands of Randy de Puniet with a sixth place finish, but while the Frenchman will be plying his trade with LCR Honda this time around, at least 'Team Green' have John Hopkins in tow, the American having finished just behind in seventh. The race also marks the home round for Anthony West.

In 250GP, Marco Simoncelli leads the way by 32 points after a fourth win of the season in Japan, the Italian edging ever closer to the title as the season enters the final stages. His closest challengers remain Alvaro Bautista, who is on a seven-race podium streak, and Mika Kallio, although his strong early season form has since tailed off.

Similarly comfortable is 125GP leader Mike di Meglio, who heads to Australia clutching a 36 point advantage. He remains ahead of Simone Corsi, while Stefan Bradl moves up to third after winning in Japan.