Rhys Irwin held off points leader Ben Currie to lead the way at the end of day one at Donington Park.
The Astro-JJR Suzuki rider, who was left devastated when two DNFs at Oulton Park all but destroyed his title chances, proved he’s still got plenty left in the tank as he took control in the afternoon session.
Irwin’s best lap of 1min 31.863secs was 0.252secs up on Currie in second place, as Luke Stapleford was third quickest in his return to the class.
Irwin’s team-mate Jamie Perrin ended the session in fourth place, closely followed by Eugene McManus.
In GP2, it was Cameron Fraser who led the way with the 18th best time overall, as Kramer Racing’s Barry Burrell was second and Harry Rowlings third.
Quattro Group British Supersport & British GP2 Championships, Combined practice:
1. Rhys Irwin (Astro-JJR Suzuki) 1min 31.863s
2. Ben Currie (Oxford Products Racing Ducati) + 0.252s
3. Luke Stapleford (Profile Road & Racing Performance) +0.290s
4. Jamie Perrin (Astro-JJR Suzuki) +0.298s
5. Eugene McManus (Completely Motorbikes Triumph) +0.357s