Conan Byrne put some substance to Shelbourne’s early pressure with the lead goal on 14 minutes, side-footing home Chris Mulhall’s pacy cross.
Shelbourne then all too easily doubled their lead six minutes before the break. Fitzgerald galloped forward, got the return from Philly Hughes’ back flick to shoot past Sheriff skipper Lee Murphy.
The woodwork again rescued Sheriff on the blow of the break when Paisley’s header from a short corner came back off the bar.
Plucky Sheriff got a goal back on 53 minutes, when Thomas Meehan saw Delaney off his line to score with an audacious 40 yard lob.
In a flurry of action, Shelbourne’s Hughes blazed a penalty over the bar after Anthony Kavanagh was booked for pulling down Fitzgerald.
Back at the other end, Meehan had an effort cleared off the line by Andy Boyle.
Sheriff levelled on 62 minutes when Molloy curled home a brilliant free-kick.
But it got better two minutes later as Molloy provided the winner, rifling home a stunner from 25 yards.
SHERIFF YC: L. Murphy; McDermott (O‘Neill, h/t), Flood, Kavanagh, Browne;
Molloy, Lester, S. Murphy, Dunne; Meehan (S. Murphy, 71), Rock (O‘Brien, 81).
SHELBOURNE: Delaney; Matthews, Boyle, Paisley, Fitzgerald; Sullivan (James, 71), Dawson (B. McGill, h/t); Mulhall (Da Silva, 76) , C. Byrne, S. Byrne; Hughes.
Referee: Darren Coombes (Dublin).