The Australian Open has been rocked by match fixing allegations.

Spaniard Marc Marquez secured his third MotoGP crown thanks to a scorching win in a drama-filled Japanese Grand Prix at the Twin Ring Motegi circuit on Sunday.

The 23-year-old Honda rider took the lead on the fourth lap and was never headed, now taking an unassailable 77-point advantage to the Australia GP at Phillip Island next weekend.

Ducati's Andrea Dovizioso finished second and Maverick Vinales on a factory Suzuki was third.