Todd, who won the earlier Supersport race in the damp from Ballymoney’s Darryl Tweed, led all the way from pole on the Milenco by Padgett’s Honda in dry conditions around the three-mile course.
Behind him, Adam McLean was comfortable in second place on his Yamaha Supersport machine throughout the seven-lap race, although a battle for the final podium place went down to the wire.
Mike Browne held third for much of the race on the Burrows Engineering/RK Racing Yamaha, but the Cork rider was coming under pressure from Derek Sheils (McAdoo Kawasaki) in the closing stages.
Sheils timed his move to perfection, passing Browne on the brakes into the chicane at the beginning of the final lap.
With Todd wrapping up his second win of the day by 5.1s from McLean, Sheils held off Browne for third, 1.3s back, with Dominic Herbertson in fifth on the Cowton Racing Kawasaki.
Paul Jordan (Prez Racing Yamaha) just held onto sixth on the line from newcomer Jamie Coward (KTS Racing/Steadplan Yamaha), with Graham Kennedy in eighth. Tweed brought the Wilson Craig Honda home in ninth.
Michael Sweeney, fifth at the end of lap one, was a retirement on his Yamaha.