Fermanagh rider Josh Elliott has been awarded his first British Superbike win after Tarran Mackenzie was hit with a three-second penalty at Silverstone.
Elliott, 22, finished 2.983 seconds behind Mackenzie, who was punished for a dangerous manoeuvre on team-mate Jason O'Halloran on the final corner.
It is also a first British Superbike success for the Ballinamallard man's team OMG Racing Suzuki.
"It's just unbelievable - a dream come true," said Elliott.
"I went back back to the motorhome after the race and when I came they said I had won it," he told OMG Racing on Twitter.
"I just can't believe it, getting my first BSB win and also the first for the team."
Elliott had to settle for second behind McAMs Yamaha-mounted Scot Mackenzie in race two and the pair share the early series lead.
Andrew Irwin was the next best of the NI contingent, coming sixth and seventh on his Honda.
Glenn Irwin crashed out in the early stages of the opener and finished 11th in race two while Clogher's Keith Farmer was 15th and 12th on the Tyco BMW.
David Allingham, from Eglinton, also crashed in the opener before a 19th-placed finish in race two.
Alastair Seeley was second in Saturday's Supersport sprint race and Sunday's feature race, behind Dubliner and defending champion Jack Kennedy on both occasions.
Lee Johnston was fourth in both races. Kennedy leads the championship on 50 points, with Seeley second on 40 and Johnston fourth on 26.
Edenderry rider Kevin Keyes, 20, won the opening round of the British Superstock 600cc series.
Rhys Irwin was fifth in both British Talent Cup races while Scott Swann was eighth and ninth.