Ryuichi Kiyonari is the new leader in the chase for the Bennetts British Superbike title after the HM Plant Honda rider enjoyed a dominant, front-running double victory in the ninth round at Oulton Park.
The Japanese rider fully capitalised on a second race machine failure that sidelined the defending champion Gregorio Lavilla on the Airwaves Ducati.
Karl Harris had claimed pole position, with the fastest ever two-wheeled lap of the Cheshire circuit, but it was his team-mate Kiyonari who made the perfect start to race one.
Leon Haslam, on the Airwaves Ducati was on the pace and moved ahead on a second lap that saw Harris fall off at Brittens.
Kiyonari soon re-asserted himself and by the end of the fifth lap was back in front and dictating terms, as behind him Haslam was coming under pressure from his team-mate Lavilla who had battled through a fast moving pack, taking both Michael Rutter and Tommy Hill.
The two Ducati riders duelled fast and furiously and at half distance, Lavilla moved second, but Haslam bit back strongly to move ahead.
"It was not easy, but very important that I won the race," said Kiyonari.
"I had a strong start, and was aware of Leon straight away and I knew that he would be quick around here.
"When I got him back, I knew that I had to up the pace so that he could not get me back again," he added, after taking his sixth win of the season by 4.673 seconds.
Lavilla took third, ahead of Shane Byrne on the Rizla Suzuki, Jonathan Rea aboard the Red Bull Honda and the Stobart Honda duo of Black Country-based Rutter and Michael Laverty, with Scott Smart, Billy McConnell and Craig Coxhell completing the top ten.
Next time out Kiyonari was swiftly away, but this time Harris in close contention as they fought for the upper hand.
Harris rewrote the record books with a super-fast third lap but it was all in vain as Kiyonari responded next time around with an even faster lap in a time of 1:35.436 at an average speed of 101.54mph.
The Japanese rider took the victory - his second double of the season - by 2.786secs from Harris, who finished three seconds ahead of Haslam, with Rea fourth ahead of Byrne, Tommy Hill, riding the Virgin Mobile Yamaha, Rutter, Hydrex Honda rider Glen Richards, Ben Wilson on the Vivaldi Suzuki and Gary Mason.
Kiyonari now leads the championship with 274 points to Haslam's 269, with Lavilla back in third place on 260.