After a goalless first half, the first of three Football South Premier League games to be played under the roof finally came to life in the 67th minute when Blair Bates opened the scoring.
Curtis Day set up Bates' eighth goal of the season with a pass in behind the defence, allowing Bates to fire past University keeper Darren Hart.
Roslyn's second goal came just a couple of minutes later, when Mike Sannum found the back of the net.
After a corner kick deflected back to Sannum outside the box, he fired a cross to Rupert Mark at the far post, only for it to sail into the top left corner.
Varsity's Henry Flood almost dragged a goal back in the 87th minute but he could not find a way past Roslyn goalkeeper Tom Stevens, who snuffed out the chance with his left boot.
Nathan Wilkie rubbed salt into Varsity's wounds with the third goal deep in stoppage time.
With the students throwing everyone forward, Wilkie found himself in acres of space on the counterattack.
After taking a long ball, he calmly shot past Hart to seal his team's fifth win of the season.
University thought it had opened the scoring in the 19th minute of the match when Jeremy Fong curled in a shot from outside the box.
However, it was disallowed as an indirect free kick.
While Roslyn, which was coming off a bye, scored three goals, it also missed a truckload of chances.
Ben O'Farrell had the best chance in the first half inside the first minute, but blazed over goal.
Day missed two of the clearest chances early in the second half.
A ball fell to the attacking midfielder inside the box in the 55th minute, but his shot dribbled wide of goal.
A minute later, a poor clearance from Hart landed at Day's feet on the edge of the box, but he could only fire the ball straight into the keeper's grasp.
But all was forgotten when he set up Bates' opener to get the ball rolling.
Northern and Caversham will play under the roof tomorrow night, while Green Island and Dunedin Technical will meet on Tuesday night.
