The Ballymoney man had the edge over Tobermore’s Adam McLean in the opening Supersport race, sealing the win by 1.7s after the pair battled it out over five laps of the three-mile course in Co Antrim.
Pole man Dunlop, riding his Yamaha R6, set the fastest lap of the race on the last lap at 102.699mph to finally break away from a dogged McLean (McAdoo Kawasaki).
England’s Davey Todd completed the top three on the Wilson Craig Honda, over nine seconds back, with Mike Browne next ahead of his Burrows Engineering/RK Racing team-mate Paul Jordan. Dominic Herbertson finalised the top six.
Derek McGee was a non-starter after he was forced to pull his Kawasaki off the grid moments before the start of the race, while another leading contender, Skerries rider Michael Sweeney, also sat out the race.
In the first event of the evening, Dunlop set a new lap record as he won the Lightweight Supersport/250GP race on his 250 Honda from McGee, who was a close second on the Faraldo Racing 450.
There was little to separate the pair throughout, with Dunlop getting the verdict by just 0.4s at the line, raising the lap record to 95.354mph after both riders shattered the old lap record multiple times.
The race was re-started over five laps after Ballymena’s Neil Kernohan crashed at Acheson’s Leap, escaping serious injury.
The main 11-race programme takes place on Saturday, with roads closed from 10am.
Kyle White