Ben Currie drew first blood at Snetterton as he led the first free practice session ahead of Eugene McManus.
The Oxford Products Racing Ducati rider clocked a best lap of 1min 52.258secs, beating McManus’s ROKiT Haslam Racing Ducati by just 0.288secs, to lead the session.
Luke Stapleford was third quickest, just ahead of Jack Kennedy as Alastair Seeley rounded out the top five.
In GP2, it was Jack Nixon who led the way ahead of team-mate Owen Jenner with Keo Walker third.
And in the Cup, Harry Cook led his ROKiT Rookie team-mate Mikey Hardie as Cameron Hall was third.
Quattro Group British Supersport and GP2/HEL Supersport Cup, FP1:
1. Ben Currie (Oxford Products Racing Ducati) 1min 52.258s
2. Eugene McManus (ROKiT Haslam Racing Ducati) +0.288s
3. Luke Stapleford (Macadam Triumph Racing) 0.644s
4. Jack Kennedy (Honda Racing UK) 0.680s
5. Alastair Seeley (Binch Pro Yamaha) +1.259s