
Champions elect: Either Valentino Rossi (right) or Jorge Lorenzo will be crowned the 2015 MotoGP champion in Valencia on Sunday.

The Repsol Honda Team's Marc Marquez leads archrival Valentino Rossi of Italy and Movistar Yamaha MotoGP during the MotoGP of Malaysia. Tensions between the two would boil over at the Sepang Circuit.

Rossi finished third, but on lap seven the Italian appeared to deliberately drive his young rival wide of the track, and -- sensationally -- kick out at the Spaniard.

Marquez lost control and crashed, later retiring from the race.

Rossi was given three penalty points on his race license by Race Direction, and crucially will start the final race of the season in Valencia from the back of the grid.

Jorge Lorenzo (left), who finished second in Malaysia behind Repsol Honda's resurgent Dani Pedrosa, is now just seven points behind Rossi in the world championship. Rossi is seeking a 10th title.

An online campaign has been launched in a bid to force a rethink by MotoGP Race Direction, appealing for its decision to be reversed.

Over 350,000 people have signed the petition, though it's unlikely to achieve its aim, with even Movistar Yamaha managing director Lin Jarvis unwilling to justify Rossi's on track behavior. The hashtag #SepangClash has been trending on social media with supporters of both Rossi and Marquez expressing passionate opinions.