Jack Dunabie got the better of rivals Ryan Frost and Jack Burrows to take the spoils in the first race of the weekend at Snetterton.
From pole, Dunabie got a clean start and led into Turn One for the first time. Frost squeezed through into the lead a few moments later, quickly followed by Burrows, who then hit the front to lead at the end of the opening lap.
What followed was a three-rider scrap which ran all the way through the remainder of the 12 lap race, the lead switching between them a number of times as the trio gapped the rest of the field.
In true class style, it all came down to the final lap. Burrows led at the end of the penultimate lap but Dunabie took the lead before they hit Turn One for the final time.
It turned out to be a perfectly timed move as the three caught and passed a backmarker which just gave Dunabie the slightest bit of breathing space.
But the fight went all the way to the line, Dunabie just holding on to win by 0.085secs as Frost and Burrows battled to the end, Frost taking second, just 0.101secs ahead of Burrows.
Tyler Humphries crossed the line fourth, some four seconds adrift of the winner with Marco Holt fifth.
R&G Moto4 British Cup, Race One result:
1. Jack Dunabie (Kovara Projects/RS Racing)
2. Ryan Frost (Fibre Tec Honda by MLav Racing) +0.085s
3. Jack Burrows (Burrows Engineering/RK Racing) +0.186s
4. Tyler Humphries (Fibre Tec Honda by MLav Racing) +4.293s
5. Marco Holt (City Lifting/RS Racing) +4.354s