New dad Billy McConnell powered to his first win of the year with a last lap move on points leader Dan Linfoot.
After controlling most of the 14-lap race, Linfoot was powerless to stop McConnell as he shoved his Honda through on the final lap and then ran wide, allowing Richard Kerr through to take second.
Linfoot managed to keep third ahead of polesitter Lewis Rollo as Alastair Seeley took fifth.
Pirelli National Superstock Championship with Santander Consumer Finance, Race One result:
1. Billy McConnell (C&L Fairburn Properties Jackson Racing)
2. Richard Kerr (AMD Motorsport) +0.412s
3. Dan Linfoot (Optimum Bikes Racing Ltd) +0.808s
4. Lewis Rollo (IN Competition/Aprilia) +6.338s
5. Alastair Seeley (SYNETIQ BMW Motorrad) +11.812s