Optimum Motorsport were the class of the field at Brands Hatch as Jonny Adam and Flick Haigh took the championship to the wire with one round remaining.
Mike Robinson took a much needed victory for Balfe Motorsport in GT4 alongside Graham Johnson in the #501 McLaren that started the race 13th in class ahead of Bens Green and Tuck in the #42 BMW, who snatched second from Martin Plowman and Kelvin Fletcher on the run to the line.
Adam passed Barwell Motorsport’s Jonny Cocker late in the race after the Lamborghini had led for most of the second stint, with the first hour punctuated by a long Safety Car period caused when Mike Newbould and Paul Vice collided on the start straight, severely damaging the Ginetta and the tyre wall.
Nicki Thiim took third from Darren Turner at the death while the championship leading Barwell Motorsport duo Phil Keen and Jon Minshaw retired late with engine failure to blow the title race wide open ahead of the decider at Donnington Park.
As Brands Hatch basked in glorious sunshine, Flick Haigh made hay and quickly built the gap that was needed to negate the 10s pit stop penalty as Andrew Howard provided stern resistance for Graham Davidson.
Dean MacDonald had fallen back to second in GT4 class behind Century Motorsport teammate Ben Green as the BMWs bossed the early stages the race in that category.
Haigh had got the gap to 12.6 seconds before the first Safety Car was brought out as the #88 Ginetta of Graham Roberts was spun off after contact with Minshaw, who was in the process of lapping the GT4 runner.
A short Safety Car period ensued, and Haigh quickly got the hammer down again to build the gap up to seven seconds before a longer Safety Car period ensued, as Mike Newbould in the #55 Ginetta collided with Paul Vice in the #44 Invictus Jaguar on the start straight.
Newbould in particularly was fortunate to be able to walk away, and indeed gesture angrily at Vice – his Ginetta totally destroyed.
Haigh only had five laps to build another gap and while she didn’t get the 10s needed, six seconds was nevertheless an impressive effort. A crowded pit lane and the associated chaos meant that her teammate Adam only lost position to Sam De Haan and Jonny Cocker.
Adam hounded Cocker for almost the entirety of the last hour, and it didn’t look like the Lamborghini would wilt under immense pressure.
But it only needed one mistake for Adam to pounce, as Cocker ran wide on the kerb at Dingle Dell with four minutes remaining to steal a vital victory ahead of the final round in September.
Jack Mitchell saw his GT4 Championship lead cut to 10 points after finishing seventh in class after starting pole with Dean MacDonald.
A 20s pit stop penalty and two Safety Car periods in the opening stint meant it was always going to be difficult for the #43 BMW to convert pole into a win.
Fortune and strategy in the pit stops melee meant that the #501 McLaren of Mike Robinson ended the round of stops in the lead, and while he didn’t drive off he was never troubled by Martin Plowman in the #53 Nissan and Scott Malvern in the #66 Mercedes.
Malvern was faster than Plowman but the Nissan was wider than ever and the Mercedes simply could not batter the door down, while Ben Tuck recovered well for the #42 BMW to climb back from eighth.
Tuck caught Malvern and Plowman at the end and quickly deposed Malvern with a minute left, before he outdragged Plowman on the run to the chequered flag.