Fresh from an exhilarating third place over team-mate and MotoGP title leader Jorge Lorenzo in Japan, Valentino Rossi continued his momentum by leading Friday practice for the Malaysian Grand Prix at Sepang.

The Italian superstar headed nearest rival Andrea Dovizioso (Repsol Honda) by 0.109sec at the end of the one-hour session. Lorenzo, who can win the title with ninth place on Sunday, was a close third, 0.174sec from Rossi.

Man-of-the-moment Casey Stoner, winner of the last two events, was fastest in the early stages - but fell harmlessly from his Ducati, after twelve minutes, when he lost the rear.

The Australian returned to the track soon after, but had to settle for fourth place, 0.436sec from Rossi.

Alvaro Bautista snatched a late fifth place for Rizla Suzuki, making the Spaniard the top rookie at a track the GSV-R traditionally performs well on.

Nevertheless, team-mate Loris Capirossi was only twelfth at a track he has won at in the past. Suzuki is yet to announce its 2011 plans.

Bautista's fifth pushed Colin Edwards down a place, but the Texan will still be happy to have continued the form he showed last weekend in Japan.

Marco Melandri, whose commitment is openly being questioned by his San Carlo Honda Gresini team, responded with a better than usual seventh. Aleix Espargaro was likewise higher than usual in eighth for Pramac Ducati.

By contrast, Tech 3's Ben Spies - the only rookie or satellite rider with a podium this year - was lower than expected on a track he has tested extensively at, with Randy de Puniet completing the top ten for Honda LCR.

Stoner's team-mate Nicky Hayden is facing his second tough weekend in a row after managing just 15th in free practice.

Dani Pedrosa, the only rider that can still beat Lorenzo to the championship, is not present this weekend after fracturing his collarbone at Motegi.

Friday practice:

1. Rossi
2. Dovizioso
3. Lorenzo
4. Stoner
5. Bautista
6. Edwards
7. Melandri
8. Espargaro
9. Spies
10. de Puniet
11. Simoncelli
12. Capirossi
13. Barbera
14. Aoyama
15. Hayden
16. Kallio