Sepang MotoGP: Pedrosa wins, Rossi and Marquez clash

The once friendly relationship between Marquez and Rossi had turned sour prior to the Sepang race when Rossi vehemently criticised Marquez's riding in the preceding Phillip Island event, accusing the Spaniard of helping Lorenzo's title bid and bearing grudges from clashes earlier in the 2015 season.

They then became embroiled in a ferocious battle for third place in the opening laps in Malaysia, repeatedly passing and repassing each other in a series of tight moves.

Rossi gesticulated at Marquez in frustration after one pass, and then after the Honda went around the Yamaha's outside at Turn 13, Rossi appeared to slow, look towards his rival and drift wide into him.

An incensed Marquez fell to the ground and then retired in the pits, while Rossi continued to finish third.

MotoGP race direction immediately announced that it would investigate the incident after the grand prix.

Lorenzo has already reduced Rossi's championship lead to seven points by finishing second.

The Spaniard dropped from fourth to sixth behind the Ducatis off the line, but outbraked both Andrea Iannone and Andrea Dovizioso into Turn 4 on the opening lap.

He then passed Rossi next time around before catching Marquez and taking his second place when the Honda ran slightly wide at Turn 4.

Lorenzo attempted to catch Pedrosa, but the polesitter always had the race under control, leading every lap and inching away to take his second win in the last three races and his third from the last four Malaysian GPs.

Neither Ducati reached the finish: Iannone slowed early on with a mechanical problem, and Dovizioso crashed out in an incident with Cal Crutchlow.

Bradley Smith charged from ninth to fourth place for Tech 3 Yamaha, ahead of Crutchlow's LCR Honda, with Pramac Ducati rider Danilo Petrucci also making good progress to beat the battling Suzukis of Aleix Espargaro and Maverick Vinales to sixth.

Pol Espargaro was ninth despite sustaining a back injury when he was taken out by Hector Barbera in a warm-up collision.

Barbera received a penalty point for the clash, which added to his tally from the earlier in the season meant he was demoted from 10th to the back of the grid. He recovered to 13th.

Stefan Bradl completed the top 10 in a strong performance for Aprilia.

RESULTS - 20 LAPS:

CHAMPIONSHIP STANDINGS: