Jason O'Halloran took a second victory in the 11th round of Bennetts British Superbikes at Oulton Park.
The McAMS Yamaha rider led from the front after starting on pole, though VisionTrack Ducati's Christian Iddon pushed him much of the way, with Danny Buchan also lurking in third.
Meanwhile, campaign leader Glenn Irwin had to retire with a technical fault, and as a result his 30-point cushion at the top is now reduced to five.
Brands Hatch GP
Salute the champion: Josh Brookes wins second BSB title
Josh Brookes had one of the most impressive performances of the day in his VisionTrack Ducati as he moved up from seventh to fourth place. Rapid Fulfillment FS-3 Kawasaki's Lee Jackson took fifth.
Bennetts British Superbike Championship, Oulton Park, Round 11 result
Jason O'Halloran (McAMS Yamaha)
Christian Iddon (VisionTrack Ducati) +0.214s
Danny Buchan (Rapid Fulfillment FS-3 Kawasaki) +1.129s
Josh Brookes (VisionTrack Ducati) +4.305s
Lee Jackson (Rapid Fulfillment FS-3 Kawasaki) +10.648s
Tarran Mackenzie (McAMS Yamaha) +11.478s
Andrew Irwin (Honda Racing) +11.819s
Bradley Ray (SYNETIQ BMW) +12.611s
Luke Mossey (Rich Energy OMG Racing BMW) +12.683s
Peter Hickman (Global Robots BMW) +15.078s
Jason O’Halloran wins Race 1 at Oulton Park
Bennetts British Superbike Championship standings after Round 11
Glenn Irwin (Honda Racing) 168
Jason O'Halloran (McAMS Yamaha) 163
Christian Iddon (VisionTrack Ducati) 146
Josh Brookes (VisionTrack Ducati) 143
Tommy Bridewell (Oxford Products Racing Ducati) 129
Tarran Mackenzie (McAMS Yamaha) 118
Kyle Ryde (Buildbase Suzuki) 117
Andrew Irwin (Honda Racing) 105
Lee Jackson (Rapid Fulfillment FS-3 Kawasaki) 99
Danny Buchan (Rapid Fulfillment FS-3 Kawasaki) 79
Josh Brookes claims ‘brilliant start-to-finish win’ at Brands Hatch
Brands Hatch GP
O'Halloran wins thrilling opener at Brands Hatch