Left with an effective 'open goal' as a consequence of Biaggi's retirement, Melandri nonetheless set about going one better as he hunted down Sykes. As it happens, Melandri wouldn't take long to get onto the back of the Kawasaki, biding his time before performing his favoured overtaking pass into the final corner.
It would prove the last decisive moment of the race as Melandri cruised home for a sixth victory of the season, a result that sees him overturn a 6.5 point deficit into an 18.5 point advantage and marks the first time BMW has ever led the World Superbike standings.
The fight for second place went down to the wire as Sykes came under increasing pressure from a resurgent Jonathan Rea and Eugene Laverty, the pair coming on strong in the latter stages to latch onto the back of the ZX-10R.
Indeed, with Sykes seemingly slower than the pair through the twisty infield, the trio would swap positions continually, but as they rounded the final lap it was Laverty who had the edge on Rea.
However, with just two corners of the race remaining, Laverty would be thrown into a high-side on the exit of turn 14, right into the path of Rea, who had nowhere to go but into the cartwheeling Aprilia.
Sending both off their bikes, even the close-following Carlos Checa
was forced to take evasive action onto the grass, a melee that duly promoted Chaz Davies from sixth to third place, a fortuitous but impressive second podium of the season for the ParkinGO Aprilia rider that goes a long way to making up for the problems that cost him a similar result in race one.
Checa recovered to fourth, still one place higher than he would have finished without the crash ahead, while Leon Camier came from 18th on the grid to claim an unexpected fifth place finish on the FIXI Crescent Suzuki, even passing Davide Giugliano in the closing stages.
Rea remounted to score some points for Honda in seventh place, just in time to hold off a train of Ayrton Badovini, Loris Baz and Lorenzo Zanetti.
Unable to replicate the form that saw him win at Silverstone, Sylvain Guintoli crossed the line 11th, ahead of John Hopkins, David Salom and Alexander Lundh, the remaining finishers in 12th, 13th and 14th.
As well as Biaggi, Laverty and Haslam, race one top five finisher Michel Fabrizio
crashed out on the opening lap, while David McFadden and Hiroshi Aoyama were involved in a collision at the final corner on the first lap too.