Jonathan Rea saw off the challenge of Max Biaggi to take victory in the opening World Superbikes race of the day at Assen.

The Castrol Honda team, run by the Ten Kate squad, are based just 50km from the circuit in the Netherlands and Rea kept his nerve to beat the reigning World Champion by 0.739 seconds, with Carlos Checa third.

The pole sitter had made a supreme getaway to lead around the first lap, but his competitors on the front row all fell back, with Biaggi and Rea moving through from the second row onto the tail of the Spaniard.

The Northern Irishman hit the front as early as lap four, with Biaggi following his past Checa a lap later, allowing the two to build a healthy lead over the rest of the field and despite a brief swap of positions on lap six, the pair held station for the remainder of the race.

Checa had a far less straightforward run after he was shuffled back to sixth by Tom Sykes, a recovering Eugene Laverty and a fired-up Troy Corser.

Sykes' early charge through from seventh on the grid, which included the fastest lap of the race, appeared to take its' toll on the Kawasaki ZX-10R, as the Brit began to fall back.

Laverty was the first to pass him on lap eight as the Yamaha continued the strong form shown in Qualifying, while Checa did likewise moments later.

Michel Fabrizio and Marco Melandri were also making progress from his poor grid positions, and they also profited from Sykes' struggles, moving up to fifth and sixth respectively.

With Rea and Biaggi trading times at the front, and Checa running a lonely third, the main focus of attention was on the three-way battle for fourth. Laverty had slipped back into the clutches of the Italian duo behind, and the Suzuki demoted him to fifth on lap 12, leaving him to fend off his teammate.

The all-Yamaha scrap eventually fell in favour of Melandri, who forced his way up the inside of Laverty on lap 15, with the Irishman losing further time and losing sixth to Corser.

Aside from Rea's stunning victory, it was a frustrating race for the British contingent. Leon Haslam rose to seventh before falling on the second lap and despite remounting, could only manage twelfth.

Tom Sykes fell all the way back to 14th and was the last classified runner after Leon Camier pulled out five laps from home. The Alitalia Aprilia had to be pushed off the grid before the start and was running round at the back before retiring.

After starting on the front row, Jakub Smrz had a miserable time. The Czech rider lost time swerving to avoid the fallen BMW of Haslam in the early stages and capped off a terrible race by falling himself three laps from the end, taking teammate Sylvain Guintoli with him.

Race Result: 22 Laps:

Pos Rider Team Gap Points
1 Jonathan Rea Castrol Honda 22 Laps 25
2 Max Biaggi Aprilia Alitalia Racing Team +0.739 20
3 Carlos Checa Althea Racing +3.572 16
4 Marco Melandri Yamaha World Superbike Team +9.508 13
5 Michel Fabrizio Team Suzuki Alstare +9.892 11
6 Troy Corser BMW Motorrad Motorsport +11.120 10
7 Eugene Laverty Yamaha World Superbike Team +15.235 9
8 Ruben Xaus Castrol Honda +30.081 8
9 Ayrton Badovini BMW Motorrad Italia SBK Team +32.071 7
10 Mark Aitchison Team Pedercini +35.000 6
11 Joan Lascorz Kawasaki Racing Team +43.287 5
12 Leon Haslam BMW Motorrad Motorsport +45.289 4
13 Barry Veneman BMW Motorrad Italia SBK Team +45.298 3
14 Tom Sykes Kawasaki Racing Team +50.764 2
  Jakub Smrz Team Effenbert-Liberty Racing +4 Laps  
  Sylvain Guintoli  Team Effenbert-Liberty Racing +4 Laps  
  Leon Camier Aprilia Alitalia Racing Team +5 Laps  
  Maxime Berger Supersonic Racing Team +12 Laps  
  Chris Vermeulen Kawasaki Racing Team +14 Laps  
  Noriyuki Haga PATA Racing Team Aprilia +16 Laps  
  Roberto Rolfo Team Pedercini +19 Laps