Malaysia: MotoGP world champion Casey Stoner threw down the gauntlet with a lap half a second faster than his rivals on the final day of the first pre-season test at Malaysia's Sepang circuit on Thursday.

The Australian, who will be chasing his third title in the top category, had missed Tuesday's first day of testing after straining his back but he returned to top the timing screens on both of the following two days.

The Honda rider set his top time of one minute 59.607, inside Valentino Rossi's circuit record, with only his second lap on Thursday morning on the new 1,000cc machine that has replaced last year's 800cc bike.

He was the only rider under the two minute mark.

Spain's former champion Jorge Lorenzo was second fastest on the Yamaha YZR-M1, 0.59 slower than Stoner in 2:00.198.

"I'm really, really satisfied, I have improved on my best record here in Sepang," said Lorenzo. "We tried a lot of things; some have been a lot better, especially one major improvement. We also know where we have to improve in the future.

"The electronics are not perfect yet, we still need to make it smoother but the bike has so much potential we are very optimistic."

MotoGP great Rossi was fifth, with Ducati satisfied with the initial performance of the bike despite the Italian being more than a second off the pace.

"This test was mainly focused on understanding if this bike is better in the front and I can say that it is," the official motogp.com website quoted Ducati Corse general manager Filippo Preziosi as saying.

(Agencies)