Newly crowned multiple champion Jack Kennedy took charge of day one as he led the way with a 1min 37.826s lap.
Kennedy’s time was 0.824secs up on second placed Harry Truelove as Lee Johnston was third, Rhys Irwin fourth and Bradley Perie fifth.
In GP2, it was Jack Scott once again who led the charge, ending the day seventh overall as Cameron Fraser was second quickest of the GP2 runners in 15th spot and Jake Archer third.
Quattro Group British Supersport and GP2 Championship, Oulton Park, combined classification:
1. Jack Kennedy (Mar-Train Racing) 1min 37.826s
2. Harry Truelove (Appleyard Macadam Racing) +0.824s
3. Lee Johnston (Ashcourt Racing) +0.936s
4. Rhys Irwin (Astro JJR Triumph) +1.115s
5. Bradley Perie (Appleyard Macadam Racing) +1.139s