France's Johann Zarco won a thrilling Australian MotoGP on Saturday with a last-lap overtake to clinch a maiden victory ahead of Francesco Bagnaia, who stretched his world championship lead.

The Pramac ace passed teammate and world title contender Jorge Martin in a nail-biting finale to take the chequered flag just 0.201secs clear of Italy's Bagnaia on his Ducati.

South Africa’s Brad Binder finished in fourth place, narrowly missing out on a podium finish after he recorded the fastest lap in qualifying.

Binder has been in good racing form, having also recorded at second-place finish in the sprint race in Japan at the end of September.

"To cross in first after so many races, it is really high emotion," said Zarco.

"I don't want to cry at the moment, but I think it will come."

Gresini rider Fabio Di Giannantonio came third at a blustery and overcast Phillip Island, with KTM's Brad Binder fourth.

Pole-sitter Martin led for 26 laps of the 27-lap race, but his soft rear tyre was cooked at the death and he couldn't hang on as grip deserted him.

The Spaniard ended fifth in a setback to his world title hopes, with Bagnaia now 27 points ahead with four grand prix left in the 20-leg season.

At least the rain stayed away during the gruelling test after the grand prix was brought forward a day to avoid forecast wild weather.

The 13-lap sprint has been shifted to Sunday, but will only take place if safe to do so, with rain and wind gusts of up to 65 kph (40 mph) expected.

Martin won the sprint in Indonesia last week, but crashed out of the main event to hand Bagnaia victory, and with it an 18-point lead in a championship race that has become a two-man show.

He was consistently fast all weekend in Australia, while Bagnaia was forced to battle through Q2 after a sluggish Friday practice.

Martin set a new lap record to grab a third pole of the year for the perfect launchpad into the race and he sped off the line to hold off Binder and Bagnaia in an ideal start.

Bagnaia didn't have the pace to keep up and Di Giannantonio soon passed him into third, and quickly widened the gap.

At the front, Martin was in a class of his own, stretching his advantage over Binder to 2.5 seconds and nearly five seconds from Bagnaia by lap 10.

The gap widened to more than four seconds, but as his rear tyre began wearing he slowed down and the chasing pack closed in, with Zarco able to snatch the last-gasp win.

Last year's race winner Alex Rins withdrew ahead of qualifying due to pain from the leg fractures he sustained in Italy four months ago.

AFP