Shelbourne 1 Sporting Fingal 2
A brace of goals inside three minutes just before the interval from Eamon Zayed and Shaun WIlliams put FAI Ford Cup finalists Sporting Fingal into the play-off final with Bray Wanderers.
Lorcan Fitzgerald hit the post before Zayed's stunning volley from a Gary O'Neill cross pushed Sporting in front on 39 minutes.
Williams doubled Sporting's lead two minutes later, shooting past Dean Delaney from the edge of the box.
Shels hit back in the second half with David McAllister scoring a penalty on 72 minutes after Sporting skipper Stephen Paisley took down David Cassidy. Striker Anto Flood was sent off for a second booking seconds later as Sporting held out for victory.
Sporting now host Bray in the first leg of the promotion/relegation decider at Morton Stadium on Friday night before the return at Carlisle Grounds on Monday.