Des Byrne scored a last minute penalty as Bohemians finally got their reward for a dominant display which sees them leapfrog UCD up into seventh place in the Premier Division table.
With the game seemingly set for a scoreless draw entering the 90th minute, UCD skipper Tony McDonnell handled Stephen Ward's cross into the College area.
Byrne was calmness personified from the spot to blast home the penalty.
Though they left it very late, the win was no more than Bohs deserved.
The sides swapped good chances in a lively first half in muggy conditions.
College striker Paul Byrne, one of four changes in Pete Mahon's side from last week's 6-0 drubbing at Shelbourne, showed his lack of sharpness after a nine-week injury lay off by wasted two good openings.
Byrne first headed wide after Bohs' keeper Stephen O'Brien totally misjudged Darragh Ryan’s corner before shooting tamely at O'Brien after Conor Sammon and Alan Mahon had worked the ball to him in a good position.
Either side of that it was Bohs, who had far more of the ball, who should have scored.
Stephen Ward shot just wide from Fergal Harkin's pass.
John Paul Kelly and Harkin then brought good stops from Darren Quigley in the College goal before the break.
Bohs maintained the upper hand into the second half.
Ward thought he had finally got the breakthrough on 63 minutes, but Quigley make a terrific stop with his right foot.
Jason McGuinness then headed over from Kelly's corner before Byrne struck to win it with that late penalty.
UCD: Quigley; Mahon, McNally, McDonnell, Kenna; McWalter (Kavanagh, 70 mins), Dicker, Finn, Ryan; Sammon, P Byrne (Brophy, 78 mins).
Bohemians: O'Brien; O'Reilly, Ferguson, McGuinness, Byrne; Harkin (O'Keeffe, 54 mins.), Kelly (Duggan, 92 mins), Farrelly, Ward; Devlin, Arkins (Leech, 58 mins).
Referee: Declan Hanney (Dublin).
