However, while Haga briefly hinted at a charge up to the back of the leader, Rea simply pumped in a new fastest lap to up the pressure. Indeed, as the race neared the mid-way point, Haga was coming under renewed pressure from Checa once more, a toll that eventually told when he crashed out of the position on lap eight at Kumho, much to his obvious frustration.
Breaking up the leading group, while Checa worked hard to try and get the gap down to Rea, it wasn't enough to put the result in any doubt, Rea crossing the line for his fourth win of the year, one that also cements his third place in the standings.
A late charge would see Checa finish just over a second behind, while Crutchlow would fade back to a lonely third, just over ten seconds adrift of the leaders.
Capitalising on accidents for Haga, Toseland and Michel Fabrizio
– the latter compounding an awful race for Ducati Xerox by falling at turn one before eventually retiring -, Biaggi battled his way back up to fourth position to eke out a further three points on his series lead over sixth place Haslam.
Making the most of his season-best seventh place starting position, Tom Sykes completed his second top five finish for Kawasaki with a spirited ride, the Briton doing a fine job to maintain a good pace throughout.
While the lead group was strung out, the battle for sixth went down to the wire as Haslam tussled with Ruben Xaus, Shane Byrne and Guintoli, the latter making an outstanding fight back from his earlier delay to join the pack late on.
Nonetheless, while Xaus was able to catch and pass Haslam five laps from the finish, the Briton dug deep on the final lap to snatch sixth place back off the Spaniard and keep the damage to his title hopes fairly minimal. Xaus finished seventh in an otherwise tough race for BMW on home soil, ahead of Guintoli and Byrne.
With just 14 riders reaching the chequered flag, Luca Scassa was tenth, Lorenzo Lanzi
11th, Ian Lowry 12th on his WSBK debut, Roger Lee Hayden 13th and Matteo Baiocco 14th.