A brief safety - car period bunched up the leaders .
When it ended a lap later , Jackson pushed his lead back up above a second - though the rear - wheel drive BMWs came back at him once leaders ' soft tyres were back up to temperature .
A brief safety - car period bunched up the leaders but when it ended a lap later , Jackson pushed his lead back up above a second - though the rear - wheel drive BMWs came back at him once their soft tyres were back up to temperature .