Returning to the Avon Tyres British GT Championship after a busy few months in the Rolex Series in America Richard Westbrook began the weekend at Snetterton by leading the opening practice session in the Trackspeed Porsche he shares with championship leader David Ashburn.

The hour long session was dominated by the fleet of five Porsches – three from Trackspeed and two from Motorbase Performance – in the 24 car field.

With only the #10 Motorbase car of Steve Parish and Benji Hetherington missing Porsches held the top four positions, Michael Caine leading the way in the other Motorbase car from the trio of Trackspeeders.

Caine's time was set early, and remained unchallenged at the top of time sheets as the leading teams cycled their drivers through to put the gentlemen driver of the pairing in the car. Daniele Perfetti taking over the controls of the #11 while Ashburn took a stint in the #31 which lay half a second off the pace at the half hour mark.

Only in the final ten minutes, with Westbrook back in the car did the times at the top start to move again, leapfrogging Caine to take the lead of the session with ten minute left, besting Caine's time by two tenths before taking a further four off his own time for a best lap of 1:50.360. Caine's time (1:50.940) remained good enough for second place, but the Porsche dominance was broken by Aston Martin, McLaren and Ferrari teams. Beechdean's Vantage was third with Matt Bell piloting the United Autosports MP4-12C to fourth on the car's British GT debut.

Behind Aaron Scott in the best Ferrari Trackspeed's #32 and #33 filled sixth and seventh with the MTECH, Ecurie Ecosse and Predator cars completing the top ten. Brands Hatch winners Jann Mardenborough and Alex Buncombe ended the session eleventh fastest in the RJN Motorsport Nissan GT-R.

Marco Attard and Hari Prozcyk in the Rhino's Leipert Motorsport Lamborghini were 14th fastest, both drivers having to learn the 300 layout at the Norfolk track.

On the weekend they can clinch the class title Team WFR duo Warren Hughes and Jody Fannin topped GT4 easily with a time of 2:00.122. 1.5 seconds separated their Ginetta G50 from the similar car fielded by Optimum Motorsport for George Murrells and Lee Mowle. Another of the G50 in the class – the Century Motorsport entry of Zoe Wenham and Dominic Evans – was fourth fastest in the session. Wenham needs to miss the podium in both races, while Fannin and Hughes win twice if the Team WFR squad are to secure the title this weekend.