Richard Cooper led the way as the Sportbike class arrived at Thruxton for the first time, beating his rivals by more than a second in FP1.
The PHR Performance Triumph rider clocked a best lap of 1min 20.780s, beating Thomas Strudwick by 1.160secs as points leader Edoardo Colombi was third.
Aaron Silvester banked the fourth best time as Harrison Dessoy rounded out the top five.
Pirelli National Sportbike with Moneybarn Vehicle Finance, FP1:
1. Richard Cooper (PHR Performance Triumph) 1min 20.780s
2. Thomas Strudwick (TS Racing) +1.160s
3. Edoardo Colombi (Gradara Corse Asd) +1.246s
4. Aaron Silvester (MIH Solutions/Macadam Racing) +1.282s
5. Harrison Dessoy (Rev2Race Yamaha) +1.428s