Further back, the battle for the final podium position went to the chequered flag, the myriad of competing riders having been broken up by an accident for Tom Sykes at the Esses on lap 17. The Kawasaki man low-sided into the corner whilst running in fourth position, forcing those following to back off.
Allowing Haslam – whose pace dropped markedly in the closing stages - a gap, it wasn't enough to hold off Checa, who stalked his way back into contention to steal the position with just two corners remaining.
The battle between Rea, Haga and Biaggi went down to the wire, with the Ulsterman coming out top in front of the two Aprilia riders. An uncharacteristically erratic performance by the reigning champion, he was even off the circuit at one stage and fell victim to a series of errors.
Having battled for the lead initially, Camier dropped back to eighth at the chequered flag with waning tyres, ahead of Troy Corser and Joan Lascorz, the latter scoring his first WSBK finish in tenth.
All 15 finishers scored points, with Sylvain Guintoli, Ruben Xaus, Ayrton Badovini, Roberto Rolfo and Mark Aitchison rewarded for reaching the chequered flag.
Elsewhere, Eugene Laverty suffered a nasty accident at Coppice on lap four and was admitted to the medical centre, while Maxime Berger suffered an unusual exit after his rear wheel came off the Supersonic Ducati, thankfully at low speed.
In the overall standings, Checa continues to lead the way, extending his margin to 14 points, this time over Melandri. Biaggi is third, Haslam fourth and Smrz fifth.