Former BTCC and Porsche Carrera Cup GB Champion Tim Harvey got his Michelin Ginetta GT Supercup career off to a winning start by taking victory in an eventful Round Thirteen, only his second race in the G55 sportscar.

With conditions changing prior to race, drivers were left with the tricky task of choosing which tyres to start with. Nathan Freke was due to start on pole after winning Round Twelve, but elected to start from the pitlane so he could change to slick tyres at the last minute. Doing the same was fellow front row starter Adam Morgan, meaning Colin White was first on the grid in third place.

As the lights went out, a good start for White saw him lead ahead of G50 runner Tom Ingram and Carl Breeze, while jumping into fourth after a superb start was Tom Sharp. He, like Harvey and Stefan Hodgetts, started from the back of the grid after poor races in Round Twelve, with all three electing for slick tyres.

Sharp was quickly up to third, passing Breeze at the Esses, before sliding past Plans Motorsport's Ingram at Sunny Out to move into second. CWS' White held onto the lead until lap two, when Sharp sliced past at Tower for the lead, while behind Breeze and Harvey made their way past Ingram. The G50 driver then lost his class lead to Andrew Richardson, who like Sharp and co had elected to start on slick tyres.

Total Control Racing's Harvey began to work his way up the field, passing team-mate Breeze on lap two, before taking White at Sunny Out two laps later for second. Hodgetts started working his way through the field also, passing Breeze at the complex for fourth, then White at Tower for third on lap five.

Later on the fifth lap though, the cars were met with heavy rain at the Complex. Sharp was first to meet it and spun off, narrowly avoiding the barriers. Behind, others weren't so lucky, with White and the G50's of Lee Pattison, Jody Fannin and Ingram all sliding off into the barriers, though all of them except Ingram were able to recover to the track and continue.

Sharp's excursion allowed Harvey into the lead, with the IDL driver recovering to second ahead of JHR Development's Hodgetts, though he lost the place soon after. Breeze was fourth, while first of the pitlane starters was Freke, who worked his way into fifth ahead of Richardson, who was enjoying a substantial lead in the G50 category after seeing his rivals going off.

At the front, Harvey held on to the win for his first Supercup win, becoming the sixth different winner in the category this season. Hodgetts took second, with Sharp taking third for only his second podium in seven races.  The gamble for slick tyres proved to be successful, with the top three being the last three drivers on the grid for the race.

Century Motorsport's Freke passed Breeze late on to take fourth, with Ciceley Racing's Morgan sixth. Seventh overall was Richardson, taking his second G50 win of the season, ahead of FML's Aaron Williamson, another of the pitlane starters. Jake Hill finished ninth on the road, but was later excluded from the results for yellow flag infringements, giving the final spot on the G50 podium to Fannin. The G55's of Alistair James and White were next up, with JHR's Pattison the last of the finishers a lap down after pitting to remove his damaged bonnet.