Jack Miller of Australia during practice for the 2017 Australian MotoGP at Phillip Island.
Jack Miller of Australia during practice for the 2017 Australian MotoGP at Phillip Island. Robert Cianflone

It's all Espargaro a-go-go at Phillip Island

MOTORSPORT: Aprilia rider Aleix Espargaro was the shock winner of the second practice session of the Australian Motorcycle Grand Prix at Phillip Island on Friday.

The Spaniard clocked 1:29.225, usurping world champion Marc Marquez by just 0.005sec.

Marquez was quickly in the groove in the session, which was faster and warmer than the morning.

But Espargaro, whose best result this year is sixth, scorched around the 4.45km seaside circuit.

Third was Ducati rider Andrea Dovizioso, again looming close to title rival Marquez, just 0.092sec back.

The 2016 Australian GP winner Cal Crutchlow hit form late, jumping his LCR Honda into fourth with a time of 1:29.329.

Maverick Vinales was running fourth when the front of the Yamaha gave way at turn eight, tumbling into the gravel trap. He returned on his second bike and ended the session fifth.

Aussie Jack Miller struggled on the Honda early in the session, but then eclipsed his morning time, clocking 1:29.446, in sixth.

Former world champions Jorge Lorenzo (Ducati) and Valentino Rossi (Yamaha) are looking down the barrel of missing the top-10 Q2 qualifying session, finishing 11th and 12th respectively.

The third practice session will start at 10.55am (AEST) on Saturday and with cool weather forecast, fast times could be hard to come by.

Alvaro Bautista crashed again, sliding the Ducati off at turn four, following his morning session tumble.

Miller's Marc VDS teammate Tito Rabat also fell, at the hairpin turn 10.

And Aussie Broc Parkes' Tech3 Yamaha slid away from under him as he accelerated through turn 11.

Miller had earlier made a stunning return from a broken leg to finish third fastest in the opening practice session.

He piloted his Marc VDS Honda around the circuit in 1:29.724, just 0.122sec behind Marquez.

Frenchman Johann Zarco was second quickest on the Tech3 Yamaha, outpacing Miller in the final minute of the session.