Richard Cooper made a late charge to grab pole position as he knocked Ben Currie off the top spot with just seconds of Qualifying to spare.
Aboard the Russell Racing Yamaha R6, Cooper found a lap of 1min 47.427secs, almost a second quicker than Currie, who had led all weekend before crashing two minutes before the flag.
Rhys Irwin will round out the front row, as Joe Collier – the highest placed GP2 runner- lines up fourth, with Lee Johnston fifth.
Cameron Fraser was second best in GP2, ending the session 20th overall with Harry Rowlings third.
Quattro Group British Supersport and British GP 2 Championships, Oulton Park Qualifying:
1. Richard Cooper (Russell Racing) 1min 47.330s
2. Ben Currie (Oxford Products Racing Ducati) +0.961s
3. Rhys Irwin (Astro-JJR Suzuki) +1.201s
4. Joe Collier (Kramer Racing) +1.522s
5. Lee Johnston (Ashcourt Racing) +1.796s