Derek Swan, who was persuaded out of retirement by manager Martin Moran at Christmas, was UCD's saviour with a winning goal to ensure their Premier Division status for the moment at least.
The students 2-1 win at Terryland Park yesterday was needed because Finn Harps defeated Longford by the same score.
Swan (34) struck for the crucial goal midway through the second half to ensure UCD enter the promotion/relegation play-off next week. Their opponents have yet to be decided, but the play-off will be over two legs.
Eoin Bennis has scored some vital goals recently and he gave UCD the lead in the 13th minute.
Alan Mahon's long free-kick was headed on by captain Tony McDonnell and Bennis turned well on the edge of the area to drill a low shot past David Forde.
After UCD missed two good opportunities, Galway equalised four minutes before the break when Darragh Sheridan toe-poked home from close range after good work by Ollie Keogh and Bobby Ryan.
In a second half they dominated, UCD got their reward on the hour. Martin's attempted shot appeared to be going wide before Swan slid in to force the ball home at the far post.
GALWAY UNITED: Forde; Keady, Clery, O'Connor, Quirke; Ryan, Murphy, Sheridan, O'Brien (Neary 69 mins); B Moran (Malee 57), Keogh.
UCD: Ryan; Mahon, Delaney, McAuley, O'Donnell; Martin (Mooney 91), Kavanagh, McDonnell, Martyn; Swan (O'Meara 89), Bennis.
Referee: A Buttimer (Cork).
