Jorge Lorenzo on top at cold and wet Phillip Island

Newly crowned world champion Jorge Lorenzo mastered treacherously cold and wet conditions at Phillip Island today to top the timesheets at the end of the opening MotoGP practice session.

Delayed by two hours after the 2.764-miles circuit was battered by strong winds and torrential rain, the Fiat Yamaha rider edged out home favourite Casey Stoner by 0.334s.

Lorenzo, who claimed his first premier class world title last weekend with third place in Sepang, clocked a best time of 1.41.146.

Stoner’s bid for a fourth successive home win saw him clock a best time of 1.41.480 as temperatures struggled to get into double figures.

American Nicky Hayden was third quickest on the factory Ducati GP10, the 2006 world champion’s 1.41.631 just 0.151s back of Aussie team-mate Stoner.

Marco Simoncelli and Marco Melandri took full advantage of the tricky conditions to set the fourth and fifth fastest time with Sepang winner and nine-times world champion Valentino Rossi down in seventh.

The Italian, who claimed a stunning win in Malaysia just five days ago, set a best time of 1.42.626 to finish just under 1.5s adrift of factory Yamaha team-mate Lorenzo.

Dani Pedrosa could not have wished for a tougher return to MotoGP action after he broke his left collarbone during practice for the recent Japanese Grand Prix at the Twin Ring Motegi.

The Spaniard was super cautious in the difficult conditions and he only completed seven laps on his Repsol Honda RC212V machine before he stopped. The Spaniard set a best time of 1.51.210.

Ben Spies didn’t take to the track until 18 minutes of the session had elapsed and when he did go out on his Monster Yamaha Tech 3 YZR-M1 machine, Australian fans only caught a fleeting glimpse of the Texan.

He completed only three laps before ending his session, the former World Superbike champion reluctant to risk crashing as an unpredictable wind lashed the circuit.