Harrison Mackay was fastest out of the blocks this morning as Round Five got underway at Brands Hatch.
The Armada SC31 Racing rider set a best lap of 1min 31.383secs to go 0.802secs clear of Taylor Rose in first practice.
Ferre Fleerackers emerged third quickest at the flag with championship leader Alfie Davidson fourth and Rhys Stephenson fifth.
Pirelli British Sportbike Championship, FP1 result:
1. Harrison Mackay (Armada SC31 Racing) 1min 31.383s
2. Taylor Rose (Timbosite Racing) +0.802s
3. Ferre Fleerackers (B.art Racing Team) + 0.874s
4. Alfie Davidson (Aprilia IN Competition Racing) +1.063s
5. Rhys Stephenson (Rocket Racing) +1.189s