Valentino Rossi has dominated Friday free practice for the Australian Grand Prix at Phillip Island, while Fiat Yamaha team-mate and title rival Jorge Lorenzo crashed with five minutes to go.

Rossi, who holds a reduced 18 point lead over Lorenzo with three rounds remaining, replaced home hero Casey Stoner at the top within 15 minutes and was undisturbed thereafter.

The Italian completed 31 laps, more than any other rider, and finished over one second clear of Lorenzo.

Lorenzo - who took his fourth win of the season last time at Estoril, while Rossi struggled to fourth - spent much of the session in fifth, before a lowside at the hairpin in the closing minutes saw him lose a further position on the final classification.

Stoner, a home winner at Phillip Island for the past two season, was Rossi's nearest rival. The Ducati star closing to within 0.135sec of The Doctor on his 22nd and final lap of the session.

Dani Pedrosa was almost half a second slower than Rossi in third for Repsol Honda, while Alex de Angelis was on fire for San Carlo Honda Gresini to be the top satellite rider in fourth.

Colin Edwards worked his way steadily up the timesheets to snatch fifth position for Monster Yamaha Tech 3 and be the final rider within one second of Rossi.

Team-mate James Toseland, who enjoyed arguably the best race of his MotoGP career by re-passing Rossi on his way to sixth in last year's Australian Grand Prix, was also on-form from the start of the session - but lowsided from his M1 while holding sixth just after the midway point.

The Englishman gamely pushed his bike back to the pits and returned to claim seventh place, just ahead of Andrea Dovizioso (Repsol Honda).

Mika Kallio also recovered from a low speed fall to claim ninth for Pramac Ducati, but team-mate Niccolo Canepa was less fortunate - falling in far more spectacular style at the fast first turn just after the halfway stage.

The Italian, making his first and last MotoGP appearance at Phillip Island, hurt his right arm in the incident and went to the medical centre for treatment.

Loris Capirossi was the top Suzuki rider in tenth position, with Nicky Hayden - who claimed his final Honda podium at last year's Australian GP - eleventh after surviving a big slide into turn one on the second factory Ducati.

The weather remained dry and bright during the session.

Friday practice:

1. Rossi
2. Stoner
3. Pedrosa
4. de Angelis
5. Edwards
6. Lorenzo
7. Toseland
8. Dovizioso
9. Kallio
10. Capirossi
11. Hayden
12. de Puniet
13. Elias
14. Melandri
15. Vermeulen
16. Talmacsi
17. Canepa