Reigning MotoGP world champion Valentino Rossi maintained his perfect start to 2010 by once again leading the way at the start of the second Sepang test.

Rossi and 2007 world champion Casey Stoner occupied the top two places during the previous two-day test earlier this month, and that pattern continued on their return - with the factory Ducati rider left 0.151sec behind the #46 Fiat Yamaha.

Rossi's best lap time, a 2min 1.068sec, was a fraction slower than his first test effort, while Stoner dipped marginally under the GP10's previous Sepang best. A 0.4sec gap then followed to top Honda rider Andrea Dovizioso, who lapped an encouraging 0.5sec faster than he had at the first test.

Fourth fastest was Loris Capirossi, who also set a new 2010 Sepang best during his first day with the new Suzuki engine, while World Superbike champion Ben Spies was the top satellite rider in fifth for Monster Yamaha Tech 3.

Spies was also 0.4sec faster than he had been at Sepang I, allowing the American rookie to edge out late-starting team-mate Colin Edwards by just 0.054sec.

Dani Pedrosa had his day interrupted by a low speed fall on the way to seventh, a few tenths slower than earlier in the month. Mika Kallio made late progress with his Pramac Ducati to claim eighth and was the last rider within one-second of Rossi.

The top ten was completed by Suzuki's Alvaro Bautista (who had a slow fall at turn one) and San Carlo Honda Gresini's Marco Melandri, also the top satellite RCV rider.

However, Bridgestone has some new tyres (front and rear) available for riders to try at this test, clouding the lap times.

"We didn't use the new tyres with Casey or Nicky because we had too many things to test, but many riders used them and improved their lap time a lot," Ducati team manager Vito Guareschi told Crash.net.

Hayden was eleventh fastest after suffering from the effects of a recent arm operation, but was able to improve on his first test lap time by 0.2sec.

"Normally Nicky is very fit but today he is not in good condition," said Guareschi. "It was only two weeks ago that he had surgery to remove scar tissue in his arm and he's been on antibiotics since. But at the end of the day he tried to push and the lap time is not bad."

Only 16 of the 17 race riders were on track today, with Rossi's team-mate and 2009 title runner-up Jorge Lorenzo forced to skip the test due to a hand injury whilst training on a motocross bike.

The second and final Sepang pre-season tests concludes on Friday.