Crutchlow fastest in wet Phillip Island FP1

Rain lashed the circuit, with Friday's torrential conditions forecast to be followed by more wet weather on Saturday before a significantly drier race day on Sunday.

After a cautious initial 10 minutes, times then tumbled over the next five, with Jack Miller the first rider into the 1m44s barrier.

That was followed a 1m43s from newly-crowned champion Marc Marquez, a 1m42s from Valentino Rossi and then 1m41 and 1m40s laps from Crutchlow.

The Briton's 1m40.957s was time on top when things settled down, 0.041 seconds ahead of Rossi, with Danilo Petrucci third, despite his Pramac Ducati shedding a winglet down the front straight.

When riders would have been heading back out for their final runs inside the final 10 minutes, the rain intensified, essentially bringing the session to an early conclusion.

That meant Crutchlow finished on top, despite only turning eight laps.

Behind the top three split by 0.053s, local hero Miller was fourth for Marc VDS Honda, having overshot Turn 1 twice during the 45 minutes.

Marquez was fifth, ahead of Ducati's Andrea Dovizioso, Suzuki's Maverick Vinales and Tech3 Yamaha's Pol Espargaro, who ran off at Turn 3 in the early stages.

Alvaro Bautista was ninth for Aprilia, ahead of Nicky Hayden, 2.055s off the pace deputising for Dani Pedrosa on the second factory Honda.

Australian Mike Jones impressed at the start of his second MotoGP weekend.

Riding for Avintia Ducati while Hector Barbera stands in for Ducati's Andrea Iannone, Jones was ninth halfway through the session, and ultimately finished 14th.

Outgoing champion Jorge Lorenzo again found the going tough in wet conditions, the Yamaha rider 20th and 4.694s slower than Crutchlow.

In his second grand prix back from injury, Tech3 Yamaha rider Bradley Smith sat out the bulk of the session, emerging for the final 10 minutes when the conditions were at their worst.

Smith finished at the foot of the times, with his seventh and final lap his fastest effort, 8.051s adrift.