Edoardo Colombi continued his successful run at Donington Park to sail to the opening win by a massive nine seconds over Richard Cooper.
The Italian took the flag 9.017secs clear of his rival, as Ash Barnes brought his Raceways Yamaha home third.
Fourth was Thomas Strudwick, as Zak Shelton took fifth.
Pirelli National Sportbike with Moneybarn Vehicle Finance, Race one result:
1. Edoardo Colombi (Gradara Corse Asd)
2. Richard Cooper (PHR Performance Triumph) +9.017s
3. Ash Barnes (Raceways Yamaha) +13.679s
4. Thomas Strudwick (TS Racing) +15.051s
5. Zak Shelton (XMT Racing) +17.264s