Phillip Island MotoGP: Jorge Lorenzo leads practice before rain

While most opted to take to the track in the opening stages, Lorenzo kept a watching brief from his garage as Avintia's Mike di Meglio set the early pace.

But as times tumbled towards the end of the session, Lorenzo twice lowered the benchmark on his YZR-M1 with a brace of fastest laps, eventually setting the pace with a best lap of 1m30.047s with 10 minutes of the session remaining.

That time would remain unbeaten as the rain intensified sufficiently in the final five minutes of the session to force riders back to the pits, with long-time leader Marquez beaten into second place for Honda.

Lorenzo's team-mate and championship leader Valentino Rossi, who will equal Loris Capirossi's record for all-time grand prix starts this weekend, wound up third after a late improvement, ahead of the second Honda of Dani Pedrosa.

Home favourite Jack Miller was an impressive fifth on his LCR Honda - and easily the fastest of the Open class runners - narrowly in front of team-mate Cal Crutchlow.

Bradley Smith, returning to the scene of his first MotoGP podium a year ago, was seventh quickest.

Italian Andrea Iannone was the fastest Ducati rider in eighth ahead of Smith's Tech 3 team-mate Pol Espargaro, while Maverick Vinales completed the top 10.

Anthony West was 24th-fastest on his return to the championship in place of Karel Abraham while Damian Cudlin, filling in for the injured Alex de Angelis, was 25th and last as he got to grips with his ART Aprilia.

PRACTICE ONE TIMES:

Pos	Rider	Team	Bike	Time	Gap	Laps
1	Jorge Lorenzo	Yamaha	Yamaha	1m30.047s	-	12
2	Marc Marquez	Honda	Honda	1m30.395s	0.348s	15
3	Valentino Rossi	Yamaha	Yamaha	1m30.572s	0.525s	15
4	Dani Pedrosa	Honda	Honda	1m30.669s	0.622s	12
5	Jack Miller	LCR	Honda	1m30.712s	0.665s	15
6	Cal Crutchlow	LCR	Honda	1m30.782s	0.735s	19
7	Bradley Smith	Tech 3	Yamaha	1m30.902s	0.855s	17
8	Andrea Iannone	Ducati	Ducati	1m30.967s	0.920s	15
9	Pol Espargaro	Tech 3	Yamaha	1m31.111s	1.064s	18
10	Maverick Vinales	Suzuki	Suzuki	1m31.240s	1.193s	15
11	Aleix Espargaro	Suzuki	Suzuki	1m31.260s	1.213s	13
12	Andrea Dovizioso	Ducati	Ducati	1m31.385s	1.338s	16
13	Nicky Hayden	Aspar	Honda	1m31.506s	1.459s	18
14	Danilo Petrucci	Pramac Racing	Ducati	1m31.670s	1.623s	15
15	Mike Di Meglio	Avintia Racing	Ducati	1m31.670s	1.623s	13
16	Hector Barbera	Avintia Racing	Ducati	1m31.702s	1.655s	11
17	Scott Redding	Marc VDS	Honda	1m31.772s	1.725s	15
18	Yonny Hernandez	Pramac Racing	Ducati	1m32.121s	2.074s	16
19	Alvaro Bautista	Aprilia Gresini	Aprilia	1m32.173s	2.126s	15
20	Eugene Laverty	Aspar	Honda	1m32.589s	2.542s	15
21	Loris Baz	Forward Racing	Yamaha Forward	1m32.756s	2.709s	15
22	Toni Elias	Forward Racing	Yamaha Forward	1m32.959s	2.912s	14
23	Stefan Bradl	Aprilia Gresini	Aprilia	1m33.558s	3.511s	16
24	Anthony West	AB Motoracing	Honda	1m33.790s	3.743s	20
25	Damian Cudlin	IodaRacing Project	ART/Aprilia	1m36.091s	6.044s	12