Elite Motorsport’s Finely Green topped the times in the Ginetta Junior free practice session ahead of qualifying at Thruxton.
Green’s 1m32.017s, set in the opening laps of the session, was almost three tenths of a second faster than the next quickest driver, team-mate Louis Foster.
Foster was one of a number of drivers to have their lap times disallowed for exceeding track limits, though he was able to remain P2.
Adam Smalley finished third quickest, 0.456s behind Green, ahead of Greg Johnson and championship leader Luke Browning.
Jonny Wilkinson and Patrik Kibble took sixth and seventh, ahead of Ruben Del Sarte, James Hedley, and James Taylor.