Edmund Best took his first win of the season as he held-off a charging Sam Laffins to take victory by 0.271s after an exciting, close-fought battle.
The Symcirrus Motorsport rider took the lead from poleman Aaron Silvester early in the race but came under threat from Laffins in the final lap as the pair swapped the lead, before Best took it back with two corners to go.
Louis Valleley was also looking threatening on the final lap but had to settle for third, with Asher Durham fourth and Silvester fifth.
Pirelli National Junior Superstock with Santander Consumer Finance, Race One result:
1. Edmund Best (Symcirrus Motorsport)
2. Sam Laffins (Uggly & Co by Binch Pro) +0.271s
3. Louis Valleley (Team Val-Tech Racing) +0.450s
4. Asher Durham (G&S Racing) +0.620s
5. Aaron Silvester (A&J Racing) +0.895s