Adon Davie ended the day on top and just 0.161secs clear of Tom Tunstall after rain spoiled play and only 10 riders hit the track.
Bob Collins ended the session third, a further half second back with Michael Tustin fourth and Andre Compton fifth.
Ducati Performance TriOptions Cup, Brands Hatch, free practice:
1. Adon Davie (JDF Racing) 1min 37.993s
2. Tom Tunstall (Motorcycle Race Parts) +0.161s
3. Bob Collins (Team Aramex/ULS) +0.741s
4. Michael Tustin (AH Performance/Breckland Utility Solutions) +0.933s
5. Andre Compton (Motorcycle Race Parts) +3.214s