Troy Bayliss closed in on his third World Superbike title after breaking his Donington duck on a chaotic day of racing. The 39-year-old is retiring at the end of the season and finally won at the Leicestershire circuit.
The Xerox Ducati rider Bayliss took race one on aggregate from British wildcard rider Tom Sykes after the race was twice stopped.
The Australian is now 101 points ahead of fellow countryman Troy Corser with just 200 points up for grabs.
Tricky conditions saw top riders crash out, including Max Neukirchner, Carlos Checa and Corser at the same corner, before the race was red-flagged on lap 10.
Sykes held a near four-second lead at the restart, but Bayliss soon passed the Huddersfield-born rider and chased down the aggregate lead before the rain returned to bring a second red flag and give him his 49th Superbike win.
Sterilgarda Ducati rider Max Biaggi was credited with third place.
The second race started in a deluge but with Japanese rider Ryuichi Kiyonari getting a good start, breaking away from Bayliss with Corser in third ahead of British riders Cal Crutchlow and Leon Haslam.
HM Plant Honda rider Crutchlow passed Corser to put himself into a podium position. Bayliss crashed at high speed with 12 laps to go and Kiyonari held on to win from Crutchlow, with Corser in third.