Recently-crowned champion Max Cook was back on the top step of the box for the ninth time this year as he took a commanding 3.466sec win over Seth Crump.
Cook led from the opening lap as he coasted to the win, as Crump enjoyed a lonely race in second place to beat Franco Bourne by a further 3.817secs.
Asher Durham won a three-way battle for fourth as Edmund Best ran wide at the last corner and Owen Jenner took fifth.
Pirelli National Junior Superstock Championship with MotoNovo, Donington Park, Race result:
1. Max Cook (Uggly & Co by Binch Pro)
2. Seth Crump (Seeeeeth) +3.466s
3. Franco Bourne (Marvel HCL Motorsport) +7.283s
4. Asher Durham (Completely Motorbikes/Affinity) +21.849s
5. Owen Jenner (Jenner Racing) +22.635s