Jorge Lorenzo's MotoGP title hopes were dragged back from the abyss after winning a chaotic Australian Grand Prix that saw championship leader Marc Marquez disqualified over a pit stop infringement.

Prior to the race all of the riders had been instructed to change their bikes on the ninth or 10th lap after Bridgestone announced that it was unable to guarantee the safety of its rear tyres beyond 10 laps following resurfacing work on the Phillip Island track.

With the race reduced from 27 laps to 19 as a consequence, it was Yamaha rider Lorenzo who coped best with the unusual circumstances as he won convincingly from pole position to breathe new life into a title battle that seemed to be petering out.

Honda rider Marquez came into the race knowing victory allied to Lorenzo finishing third or lower would hand him the title in his debut season, but instead he saw his lead reduced to 18 points with two rounds remaining after earning a black flag for failing change his bike on schedule.

Marquez's team-mate Dani Pedrosa was the first of the front-runners to pit at the end of lap nine while Lorenzo followed a lap later, but Marquez did not peel off until lap 11, earning him disqualification for "exceeding the maximum number of laps before having to pit in".

Marquez's error allowed Lorenzo an untroubled run to the flag, with Pedrosa coming home in second place to maintain his own title hopes, with the Spaniard now 34 points off the leader.

Lorenzo's team-mate Valentino Rossi completed the podium, with British duo Cal Crutchlow and Bradley Smith fourth and sixth respectively on the Tech 3 Yamahas, sandwiching Alvaro Bautista (Gresini Honda) in fifth.