Spa British GT: Trackspeed Porsche beats Motorbase Aston to victory

Keen passed Michael Caine in the Motorbase Aston Martin Vantage, which had led since the start, four laps from the end of the one-hour race to cap a superb turnaround for the Trackspeed squad.

Rory Butcher and ex-British Touring Car Championship racer Jeff Smith completed the podium to make it two Motorbase Astons in the top three.

Rain had fallen throughout the morning but stopped less than an hour before the race start, prompting a frantic series of pitstops as the formation laps began.

Minshaw was one of several drivers to return to the pits to switch to slicks before lining up on the grid, and was at the head of the queue - which included the pole-claiming Ecurie Ecosse BMW Z4 of Marco Attard and Alexander Sims - that joined the field for the second formation lap.

At the front, the two Motorbase Vantages had gambled on starting from slicks - the Triple Eight BMW of Derek Johnston and Luke Hines the only other car to do so - and they inherited first and second as the majority of their rivals pitted.

Ahmad Al-Harthy led for the entirety of his stint before handing over to Caine, but Minshaw had made swift progress through the field and was seven seconds behind when they pitted in tandem.

Keen resumed the chase and with 15 minutes to go had cut the gap to two seconds, and once that was halved on the next lap he drafted the Aston through Eau Rouge and onto the Kemmel Straight, with the 911 ahead by the time they reached Les Combes.

Caine remained comfortably clear of Butcher, who along with Smith claimed his first podium in the series, with Sims charging to fourth in the Barwell-run Z4.

He had recovered well in the opening laps of his stint before falling outside of the top 10, but slick work in the pits and a strong out-lap meant Sims vaulted back up the order.

The ex-single-seater racer finished ahead of the United Autosports Audi R8 LMS ultra of Matt Bell and Mark Paterson, with guesting Le Mans 24 Hours ace Emmanuel Collard sixth alongside Francois Perrodo in the AF Corse-run Ferrari 458 Italia.

Championship contenders Andrew Howard and Jonny Adam had a difficult race, with Attard slashing their lead to just 1.5 points.

While Howard made solid ground early on having switched to slicks at the same time as Attard, a success penalty following their victory at Snetterton dropped them to 12th before Adam salvaged 10th. That became ninth when the Tom Sharp/Colin White Ginetta G55 was dropped from eighth, its best finish of the season, to 14th with a 30-second penalty for a collision with the second Trackspeed Porsche.

In the GT4 class, Devon Modell narrowly held on to win in the TF Sport Vantage V8 he shares with Andrew Jarman. Gavan Kershaw (Lotus Evora) made a late charge to steal second from the other Aston of Jake Giddings and Ross Wylie, but the cars swapped places once the Lotus was handed a 10-second penalty after the race for causing an avoidable collision.

Results - 23 laps:

Pos  Drivers          Team/Car                    Time/Gap
 1.  Keen/Minshaw     Trackspeed Porsche      1h00m27.335s
 2.  Caine/Al Harthy  Motorbase Aston              +1.311s
 3.  Butcher/Smith    Motorbase Aston             +13.570s
 4.  Sims/Attard      Ecurie BMW                  +32.371s
 5.  Bell/Paterson    United Autosports Audi      +37.931s
 6.  Collard/Perrodo  AF Ferrari                  +46.409s
 7.  Lyons/Lathouras  AF Ferrari                  +53.330s
 8.  Schulz/Bailey    Horsepower Aston          +1m02.063s
 9.  Adam/Howard      Beechdean Aston           +1m02.641s
10.  Appleby/Tandy    Generation Bentley        +1m12.284s