Luke Stapleford set the pace this morning as he stormed to the best lap of the opening free practice session at Brands Hatch.
The Macadam Triumph Racing rider pulled out a 1min 27.801sec lap on his last run to go 0.211secs clear of points leader Rhys Irwin.
Third quickest was 2024 champ Jack Kennedy, who will be looking to reclaim the title on Sunday for the Honda Racing UK squad and finished the opening session 0.364secs behind Stapleford.
TJ Toms was fourth quickest ahead of Oliver Barr as Ben Currie, who sits just four points behind Irwin in the championship chase, could only manage the sixth best time.
In the Cup class, Keo Walker led the way ahead of Stephen Thomas and Josh Bannister.
Quattro Group British Supersport Championship, FP1:
1. Luke Stapleford (Macadam Triumph Racing) 1min 27.801s
2. Rhys Irwin (Gearlink Bike Performance 51) +0.211s
3. Jack Kennedy (Honda Racing UK) +0.364s
4. TJ Toms (G&S Racing Kawasaki) +0.462s
5. Oliver Barr (Binch Pro Ducati) +0.464s