Moira rider Ian Lowry secured his maiden British Superbike victory in Sunday's opening race at Thruxton.
The Padgett's Honda rider overtook reigning series champion Tommy Hill in the closing stages to record his first success in the class in 56 attempts.
"The bike is pretty new so it's great to be winning races early on. I have to thank Clive Padgett for signing me up after a few lean years," said Lowry.
Keith Farmer took his second successive win in the Superstock 1000cc class.
The Clogher racer now leads Jason O'Halloran by 18 points in the championship standings.
Michael Laverty was sixth in Superbike race one and Alastair Seeley 15th, but it was their compatriot Lowry who took centre stage at the Hampshire circuit.
"We started the weekend with a good setting and we stuck to it," explained Lowry.
"The team is good and the bike suits my riding style - I've adapted to the Honda well," added the 25-year-old.
Lowry finished fifth in the second Superbike race of the day, which was won by Tyco Suzuki rider Josh Brookes.
Toomebridge man Laverty was 13th and Seeley, from Carrickfergus, 21st in that event.
Lowry leads the championship by two points from Australian Brookes.
Dubliner Jack Kennedy was fourth in British Supersport race one for the Mar-Train Yamaha team, while Glenn Irwin was 12th. In race two Kennedy was second and Irwin seventh.
William Dunlop took sixth and seventh place finishes on his 125cc machine.