Richard Cooper has ended the opening day at Thruxton at the top of the Sportbike timesheets after clocking a hot lap of 1min 20.092secs.
The inaugural champion, back for the remaining rounds of the season with the Moto Twelve CFMOTO squad, topped the combined practice times, 0.393secs clear of Carl Harris.
Third fastest was Adon Davie, ahead of Sullivan Mounsey who was fourth with Lewis Smart rounding out the top five.
Pirelli British Sportbike Championship, Combined Practice:
1. Richard Cooper (Moto Twelve CFMOTO) 1min 20.092s
2. Carl Harris (ROKiT Rookies) +0.393s
3. Adon Davie ( Moto Twelve CFMOTO) +0.590s
4. Sullivan Mounsey (Symcirrus Motorsport) +0.590s
5. Lewis Smart (Smart Racing) +0.612s