Stoner takes advantage in Assen as Lorenzo crashes out early

(CNN) -- World champion Casey Stoner boosted his hopes of defending that title with victory at an incident-packed Dutch MotoGP at Assen Saturday.

A first corner accident saw San Carlo Honda Gresini's Alvaro Bautista end the hopes of title leader Jorge Lorenzo, the Yamaha team leader clearly unhappy at the premature end to his race.

It left the Hondas of Stoner and Dani Pedrosa to dominate affairs with Lorenzo's teammate Ben Spies in pursuit.

Stoner took a lead he maintained to the checkered flag, closely followed home after a thrilling duel by Pedrosa.

Andrea Dovizioso in the Monster Tech Yamaha overhauled Spies for third.

His teammate Cal Crutchlow of Britain continued his fine season with fifth, just ahead of former world champion Nicky Hayden of the United States on his Ducati.

Hayden's teammate, seven-time champion Valentino Rossi, continued his disappointing season back in 13th after being forced into the pits for a late tire change.

Stoner, who had started on pole, has pulled level with the unfortunate Lorenzo at the top of the overall standings.

Bautista is under investigation after the crash and apologized to Lorenzo for ending his chances.

"At the end I arrived so fast into the corner and I tried to stop the bike to stop Lorenzo from dropping out. I'm so sorry for him," he told BBC Sport.

Spain's Marc Marquez, riding a Suter won the Moto2 category race, while his compatriot Maverick Vinales was first across the line in the Moto3 race on his FTR.