Harrison Dessoy emerged more than a second quicker than nearest rival Lucas Brown with a 1min 40.919s lap in FP1.
The Microlise Cresswell Racing/Eastern Garage Racing rider was 1.2s clear at the top of the timesheets, with Ryan Frost third.
Fourth quickest was Ollie Walker, who finished the session just 0.073secs clear of Josh Bannister.
R&G British Talent Cup, FP1:
1. Harrison Dessoy (Microlise Cresswell Racing/Eastern Garage Racing) 1min 40.919s
2. Lucas Brown (Amphibian Scaffolding/SP125 Racing) +1.200s
3. Ryan Frost (Talentum Motorsport by Azure Notions) +1.663s
4. Ollie Walker (Wright Morgan/SP125 Racing) +1.881s
5. Josh Bannister (Dunsley Heat Racing) +1.954s