However, he wouldn't need to in the end as Bayliss became the first casualty of the tricky conditions. Although the track was not quite as sodden as it had been earlier, Bayliss would lose his Xerox Ducati coming under Starkey's Bridge, a crash that looked nasty but otherwise left him unhurt.
Now Crutchlow was second and as the rain made an intermittent presence over the remaining laps, the erratic, but nonetheless enjoyable, looking Kiyonari began to see his advantage over the wild-card rider drop.
With the gap getting to as low as 0.7secs with only a couple of laps to go, the arrival of more rain would eventually prompt Crutchlow to ease off and let Kiyonari claim his third win in four races.
Nonetheless, Crutchlow was still an excellent second to complete a fine weekend for the British contingent.
It could have been better if Haslam had been able to maintain his early momentum and catch Corser. However, while a mistake left him seemingly happy to settle for fourth, he would eventually end up off the track when he crashed at the Old Hairpin with just two laps remaining. It meant Corser was a comfortable third, a good result given how often he has been off the bike this weekend.
Fourth instead fell to another of the British riders, James Ellison, who defied a run through the gravel at Coppice midway through the race to battle back to fourth. Setting several fastest laps on the way, Hydrex Bike Animal Honda have certainly made their mark this weekend.
Michel Fabrizio left it late to come good on the second Xerox Ducati after managing to get the better of Biaggi, Gregorio Lavilla and Ruben Xaus, the quartet fighting for position for much of the race.
Carlos Checa was ninth, ahead of Tom Sykes, the race one podium winner seemingly unhappy with his bike in the wet conditions. Lorenzo Lanzi, Jakub Smrz, Roberto Rolfo, Max Neukirchner and Regis Laconi rounded out the points places.
Meanwhile, Noriyuki Haga had the ignominy of being disqualified after failing to serve a drive-thru penalty, given after he didn't stop immediately in the first race following his engine failure. The Japanese rider had pitted once already, but it was not in the allotted window and, as such, was black flagged.