Jonathan Rea (Castrol Honda) overcame the early battles at Assen to record his and Honda's first win of the 2011 season, beating Max Biaggi (Aprilia Alitalia) by 0.7 seconds and championship leader Carlos Checa (Althea Racing) by 3.5 seconds in race one.

Marco Melandri (Yamaha World Superbike) overcame a slow start to claw his way back to fourth, just ahead of Michel Fabrizio (Suzuki Alstare). With Troy Corser (BMW Motorrad Motorsport) behind Fabrizio there were six different machines inside the top six places. Top Kawasaki runner was Mark Aitchison (Pedercini Team Kawasaki) in tenth. Leon Haslam, Corser's team-mate, survived a fast early crash to recover to a top-12 finish.

Results - Race One1, J Rea, Castrol Honda2, M Biaggi, Aprilia Alitalia Racing Team3, C Checa, Althea Racing4, M Melandri, Yamaha World Superbike Team5, M Fabrizio, Team Suzuki Alstare6, T Corser, BMW Motorrad Motorsport7, E Laverty, Yamaha World Superbike Team8, R Xaus, Castrol Honda9, A Badovini, BMW Motorrad Italia SBK Team10, M Aitchison, Team Pedercini11, J Lascorz, Kawasaki Racing Team14, T Sykes, Kawasaki Racing TeamC Vermeulen, Kawasaki Racing Team DNF