Joe Talbot took control as the Quattro Group British Supersport pack headed out for the first time this weekend, holding off Rhys Irwin by 0.141secs.
Binch Pro Ducati’s Talbot clocked a best lap of 54.244secs in wet conditions at the short Scottish track to end the opening session on top.
Defending champ Jack Kennedy had led earlier in the session, but had to settle for third at the flag, with Luke Stapleford fourth and Ben Currie fifth.
The Cup class was led by Keo Walker, who finished the session 13th overall, with Ben Tolliday second and Josh Bannister third.
Quattro Group British Supersport Championship, FP1:
1. Joe Talbot (Binch Pro Ducati) 54.244s
2. Rhys Irwin (Performance 15) +0.141s
3. Jack Kennedy (Honda Racing UK) +0.217s
4. Luke Stapleford (Macadam Triumph Racing) +0.286s
5. Ben Currie (Moto Rapido Ducati Racing) +0.347s