Dunlop, a publican from Ballymoney, trailed Phil McCallen for much of the race, but he charged clear when his Castrol Honda team-mate ran out of fuel with six miles remaining. It was a case of deja vu for McCallen, who suffered the same fate with victory in sight in this race last year.
Dunlop also had problems. The right foot rest broke early on, and he had to use the exhaust or drag his foot on the road surface.
'I thought I wouldn't make it on the first lap, but decided to keep going, and it paid dividends,' the 42-year-old said. 'I am starting to feel a bit tired, having done a lot of laps this week, but I'm not thinking of quitting. I am enjoying it all too much.'
Jim Moodie, from Glasgow, put up with considerable pain to claim his second victory in as many days, winning by 1min 17.6sec in the Supersports 400.
He won Tuesday's Single Cylinder, but then crashed while leading the Supersport 600, sustaining hand injuries.
'I didn't notice the injuries until my nearest rival, Iain Duffus, dropped out then I had time to think about them,' Moodie said.Reuse content