This was Tom‰Ûªs seventh straight win at Donington and his third race victory of the season on the new model Ninja ZX-10R.
Rea ran out third, 9.808 seconds down, after his earlier issues and despite having the pure pace to challenge all the way to the flag.
With championship second place runner Chaz Davies crashing out of the race, Rea has a 58 point lead as he approaches tomorrow‰Ûªs second day of Donington race action, while Sykes is still overall third and now only three points behind Davies at the halfway point of the year.
"I have no real reason why I have won so much at Donington Park but what makes it more rewarding today is that I had to fight for it," Syke said after the race. "I got a good start but a couple of the guys really made some strong passes to get in front. I am sure if we could have had some good steady laps at the beginning we also would have had good pace - but I am happy that I had to fight for it.
"I had some issues myself from the bike, which is unusual, but the good thing is that even considering these I dug deep and came out with 25 points. After six laps I could understand what was going on and I thought it would be very difficult, maybe impossible to win. We kept plugging away and I had to manage the bike a bit differently in some areas to compensate. Overall I am really happy to win and the plan tomorrow is to be stronger, safer and more consistent.‰Û