Jason Plato led home a dominant MG one-two to win the opening race of the day ahead of Sam Tordoff at Silverstone.
Plato, starting from pole, controlled the race from start to finish after making a clean getaway ahead of his younger team mate Tordoff who briefly dropped to third at the expense of eBay Motors' Colin Turkington before regaining the position on lap 3.
The MG pairing then about establishing an unbeatable gap ahead of the field – their charge briefly halted thanks to a three-lap safety car interval triggered by the high-speed collision involving Andy Neate, Mark Foster and Will Bratt
which occurred at Woodcote corner.
Plato's victory now draws him to within 49-points of championship leader Andrew Jordan who picked his way through the field to finish a handy sixth from starting tenth on the grid.
Honda's Matt Neal clinched the final step on the rostrum by the skin of his teeth, crossing just eight-thousandths ahead of Turkington's BMW in fourth while Rob Collard, who ran the soft tyre, and Pirtek's Jordan followed home fifth and sixth in close company.
Ciceley Racing's Adam Morgan finished where he started in seventh ahead of Airwaves Racing duo of Aron Smith and Mat Jackson in eighth and ninth.
Dave Newsham endured a difficult race despite starting from the third grid slot. The Speedways man after initially losing out at the start then suffered a spin during Brooklands dropping him down the field before coming back to finish tenth.
Honda's Gordon Shedden failed to make any satisfactory progress to limp home eleventh, meaning the defending champion drops to fourth in the overall standings.
Lee Wood was the top S2000 runner in 20th overall with Liam Griffin bringing his Focus home in 23rd.