Gibernau was seventh at Sepang last season

The Spanish Telefonica Movistar Honda rider had a fastest lap of two minutes 03.299 seconds during the morning session at the Sepang circuit.

He was 0.136 secs ahead of Suzuki's Kenny Roberts Jr with Loris Capirossi third quickest on the Ducati Marlboro.

Valentino Rossi, who needs fourth place or better to retain the title, was fourth fastest on a Gauloises Yamaha.

The Italian has won three times in the last four years at Sepang and will be chasing his 10th victory of the season in the 21-lap race.

He is chasing a fourth consecutive world crown in motorcycling's blue riband class.

Marco Melandri, Gibernau's team-mate, made a surprise return to action just five days after undergoing surgery on the foot injury he sustained in a collision with Rossi at Motegi.

Londoner Shane Byrne, appearing as replacement for injured Camel Honda rider Troy Bayliss, lapped 18th fastest in his first session aboard the Honda RC211V.

Cumbria's James Ellison, who is competing despite an injured left elbow, was 20th aboard the WCM Blata.