Tom Tunstall took charge of free practice as he led David Shoubridge by 1.466secs with a best lap of 1min 41.706secs.
Phil Atkinson was once again third quickest, ahead of fellow South African Blaze Baker with Adon Davie rounding out the top five.
Ducati Performance TriOptions Cup, Oulton Park, FP1:
1. Tom Tunstall (Motorcycle Race Parts) 1min 41.706s
2. David Shoubridge (Rich Energy Ducati) +1.465s
3. Phil Atkinson (Q Oil Treatments/Unique Motorsport) +1.603s
4. Blaze Baker (Trackdemons Racing Powered by HMY) +2.037s
5. Adon Davie (JDF Racing) +2.884s