Marc Marquez beats brother Alex to Australian MotoGP pole

World champion Marc Marquez beat brother Alex to clinch pole position Saturday at the Australian MotoGP, but he needed some white-knuckle laps to do so after crashing early on.

Under dark clouds and with spots of rain falling, the Spanish Ducati rider powered round the waterfront circuit at Phillip Island with a blistering lap of 1min 34.203sec.

It was enough to topple Alex, also on a Ducati, by a massive 1.494sec, with Honda's Johann Zarco third to join them on the front row.

Championship leader Jorge Martin, who is two points clear of Marc Marquez with five rounds of the season left, was fourth, but well off the pace.

Home hero Jack Miller and last year's winner Raul Fernandez accompany him on the second row.

Marco Bezzecchi, who won last week in Indonesia and is third in the standings, 46 points behind Martin, will start in ninth.

"You cannot crash in the first lap because it means that you don't have a lap time. So it was a big mistake," said Marc Marquez.

"But the team was ready with the other bike, I kept focus and that last lap was a good lap."

Marquez, who dominated morning practice, slid off on his first flying lap at Turn 4 as he pushed too hard.

Undeterred, he limped back to the pits and climbed onto his spare bike and immediately set the new fastest time.

It was surpassed by Zarco, but Marquez came back out at the death to blitz a new quickest time and secure his 78th career pole.

The sprint race is later Saturday and the main event on Sunday, with thunderstorms forecast.

They will go ahead without Honda's Luca Marini, who has a virus and will take no further part in the weekend action.

Phillip Island has been a staple on the calendar since 1997 but the Australian race is moving next year to a street circuit in Adelaide.