Nori Haga took advantage of Ben Spies' race two crash in Holland to stretch his lead in the Superbike World Championship to 60 points.

Yamaha rider Spies was leading race two at Assen but went off at turn one on the second lap and parted company with his bike which went over the crash barriers.

Spies, who had edged the Ducati Marlboro machine of Haga in race one, saw his rival take his fourth win of the season ahead of the Stiggy Honda of Leon Haslam.

Following up his third in race one, Haslam held off the challenge of Ducati rider Michel Fabrizio to record his best result in World Superbikes which sees him third in the points standings.

Fabrizio saw his hopes of a podium disappear on the final lap of race two when he was passed by Jakub Smrz on the Guandalini Ducati who also recorded his best result.

Spies had won race one after he edged the battle with Haga in the closing stages.

Haga had looked set for the win before Spies made his move three corners from the end of the race to record his fourth win of the season.

Third went to Haslam who had fought with the two factory riders for the whole of the race.

Tom Sykes was a distant fourth, with the Aprilia of Max Biaggi fifth.

Smrz, Jonathan Rea (Honda), Regis Laconi, Michel Fabrizio (Ducati) and Troy Corser (BMW) completed the top 10.

With Haga, Haslam and Smrz occupying the podium slots and Fabrizio fourth in race two, Rea was fifth and Sykes sixth.

Carlos Checa (Honda), Shane Byrne (Ducati), Max Neukirchner (Suzuki) and Corser completed the top 10.