Jason O'Halloran took the lead from the start, with Josh Brookes taking second spot, before Andrew Irwin re-established himself just behind O'Halloran.
Brookes then displaced them both as he took the lead on lap four, and approaching the halfway line he was able to hold off Peter Hickman and Tommy Bridewell, who moved into second and third respectivley.
O'Halloran sneaks victory from Mackenzie in Race 3 at Silverstone
Scott Redding climbed into fourth, as Irwin (fifth) and O'Halloran (sixth) were pushed further down.
On lap nine, the red flag came out for rain, with the riders forced to come in.
From the restart, Brookes, Hickman and Irwin made up the top three in that order.
On the seventh lap of the 13 lap restart, another red flag came out when Glenn Irwin's bike burst into flames, forcing yet another pause, with Brookes, Andy Irwin and Dan Linfoot on course for the podium.
After the second restart, the pack raced the remaining eight laps. Hickman jumped into second before irwin regained his spot.
Brookes was able to hold onto the top spot and took the chequered flag after an eventful second race.
Irwin claimed third ahead of Hickman, with Scott Redding leaping into a late second place, however Redding failed to serve a long lap penalty and lost the position following a 15 second censure.
Honda rider Andrew Irwin defended a late challenge from Scott Redding to claim a victory in Race One.
Scott Redding held pole, ahead of Tommy Bridewell and then Peter Hickman.
Hickman and Irwin then moved up into first and second respectively from the off, and pulled away from the rest of the pack, before Irwin swept to pole briefly, with Hickman back in second on lap two.
Meanwhile, Jason O'Halloran edged up into third with Redding down into sixth.
On lap four, O'Halloran took advantage of Irwin and Hickman fighting it out for the lead and moved ahead of them both. Christian Iddon then took the chance to move into third.
At the halfway point, Redding had moved up into fifth, and Hickman pounced to reclaim the lead. That move allowed Iddon to capitalise on O'Halloran's distracted attention to move into second. Redding battled his way back to third with six laps remaining.
With three laps to go, the front three were O'Halloran in first, Irwin in second, and Josh Brookes in third, in their own tight pack.
Irwin made a dramatic move into pole on the penultimate lap. In the final lap, Redding took third, and then second, and on the final approach Redding make a desperate wide lunge for victory, but Irwin was able to hang on.
‘Friends again?’ - Mackenzie beats O'Halloran in Race 2 as Yamaha bounce back