Stoner and GP9 lead Valencia test.

Casey Stoner, winner of Sunday's season-ending grand prix at Valencia, joined almost all his 2009 rivals in returning to the track for the start of a post race test on Monday - and continued to dominate, this time on next year's Ducati Desmosedici GP9.

The 2007 world champion, who will undergo bone graft surgery on his injured wrist on Thursday, won Sunday's race by a comfortable 3.4sec over Dani Pedrosa, with newly crowned six time world champion Valentino Rossi a further nine seconds behind in third.

Those riders and positions were replicated on Monday, when Stoner's second ride on the GP - which features a carbon-fibre chassis - ended with the Australian having ducked under his fastest race lap on the GP8 by 0.118sec, as all riders began work with the new, wide operating range, 'single tyre' spec Bridgestones.

"The feelings from this first day of testing in Valencia with the GP9 have been definitely good," said Stoner, who first rode the GP9 at the post-race test in Catalunya.

"We tried many things, some worked well, others less so, but this is normal because the bike is quite different in its characteristics and in its reactions compared to the GP8. We still have other things to try but the feeling is already excellent and in fact we were able to lap consistently quickly.

"I am very happy with the behaviour of the engine that seems to me to be more progressive and predictable. The bike is more stable in braking which is really saying something because the GP8 was already very efficient from this point of view. We have to work more on the rear set-up but the potential is good, it is just a question of finding the right set-up.

"Also as far as the tyres are concerned I am satisfied, above all the specification that we used this morning, with which we were able to maintain an excellent rhythm for thirty laps. A good start from this point of view.

"I think that Nicky [Hayden, twelfth fastest] is content with his first day at Ducati, he continued to improve during the day and I am sure that with a few more days with the bike he will find himself in good shape," said Stoner of his new team-mate.

Pedrosa, riding with some new parts on his factory Repsol Honda RC212V, lapped 0.208sec slower than Stoner as he also trimmed a little time off his ultimate race lap. The same was true of Rossi, who only began testing at 3pm, but was able to put a prototype version of the 2009 YZR-M1 0.154sec under his best lap on this year's machine.

But with the top three riders in the world championship all remaining with their 2008 teams and tyre supplier for next season, most attention was focussed further down the order - with no less than eight riders appearing with their 2009 teams for the first time on Monday.

Fastest of the new signings was Repsol Honda's Andrea Dovizioso. The young Italian, who concluded his final race for JiR Team Scot with fourth place in Sunday's race, worked his way steadily up the 18-rider timesheet to end his first day on a pneumatic-valve Honda and Bridgestone tyres in eighth position.

Dovi's best lap was 1.2sec from Stoner and just 0.126sec from Fiat Yamaha's Jorge Lorenzo, who beat Dovizioso to the 2008 Rookie of the Year title. Lorenzo was the fastest of the former Michelin riders, despite a fall, and appeared to have little trouble extracting speed from Bridgestone rubber as he clipped 0.334secs from his fastest race lap on Sunday.

Next fastest of the new signings, behind Dovizioso, was Marco Melandri in tenth position. After a disastrous season at Ducati, Melandri looked instantly more comfortable on the ZX-RR, lapping just 0.022sec slower than the team's 2008 rider John Hopkins and beating both his best race and qualifying lap on a Desmosedici.

2006 world champion Nicky Hayden, who has replaced Melandri alongside Casey Stoner, closed the day in twelfth position - the American's best time on the GP9 being 1.496sec from Stoner but within 0.6sec of his best on a Michelin-shod RC212V in the grand prix.

Hayden and Dovizioso were the only riders to lap slower than they had done in the race, but they are also the only riders on the 2008 grid to have changed both team and tyre supplier. Hayden's best lap was 0.284sec slower than Dovizioso on Monday.

Toni Elias marked his return to Honda Gresini with 13th position 1.6sec from Stoner, while a 0.3sec gap separated the Spaniard from countryman Sete Gibernau.

Gibernau, a former double MotoGP World Championship runner-up Gibernau, will end a two season retirement by returning to MotoGP action in 2009 and got acclimatised to the newly formed Onde 2000 Ducati outfit on Monday.

There will be three class rookies present on the 2009 MotoGP grid and the fastest of them on Monday was 250 grand prix title contender Mika Kallio. The Finn put his Alice Ducati 0.342sec behind Gibernau's Desmosedici as he all but equalled Elias' best race lap on the machine. Gibernau, Kallio and Canepa were riding this year's GP8.

Kawasaki test rider Olivier Jacque slotted between Kallio and team-mate Niccolo Canepa, the Ducati test rider surprisingly slower than Desmosedici newcomer Kallio, albeit by just by 0.2sec.

Yuki Takahashi, who finished second in Sunday's 250GP, rounded out the field on Dovizioso's former machine. The Japanese increased his pace throughout the day to finish just 0.2sec from Canepa.