David Shoubridge pipped Tom Tunstall to the line by just 0.257s to take the opening win at Donington Park.
The pair, who had dominated free practice and qualifying, were straight back at it as the 15-lap race began as they gapped the field by more than 16 seconds by the flag.
Third over the line was former champ Phil Atkinson, ahead of Max Lofthouse and Michael Tustin.
Ducati Performance TriOptions Cup, Donington Park, Race One:
1. David Shoubridge, Rich Energy Ducati
2. Tom Tunstall, Motorcycle Race Parts +0.257s
3. Philip Atkinson, Q-Qi Treatments/unique Motorsport +16.774s
4. Max Lofthouse, JDF Racing +17.484s
5. Michael Tustin, AH Performance/Breckland Utility Solutions +26.886s