Marc Marquez won his home Spanish Grand Prix and took the overall MotoGP lead on Sunday after the reigning champion's main rivals collided spectacularly.

The Honda rider was in a race of his own for the last eight laps after the Ducati pairing of Andrea Dovizioso, the previous championship leader, and Jorge Lorenzo collided with Honda's Dani Pedrosa while fighting for second place.

Pedrosa, who had wrist surgery less than a month ago, was thrown high over his bike after trying to go past the two Ducatis on the inside.

Lorenzo came across into the corner as Dovizioso went wide, colliding with Pedrosa and sending the two Ducatis into the gravel. All three riders walked away from the crash.

French Tech3 Yamaha rider Johann Zarco was gifted the runner-up slot, 5.241 seconds behind, and is now Marquez's closest rival in the championship.

Four times world champion Marquez, who started the race from fifth place, now has 70 points after four races to Zarco's 58. Dovizioso dropped to fifth overall with 46.

Italian Andrea Iannone finished third for Suzuki.