Gavin Doherty scored the goal as Aileach reached the Ulster Junior Cup final for the first time in their history.
Buncrana Hearts 0 Aileach FC 1
After an even opening period the visitors had the first effort but Dermot Doherty saw an effort saved by Seamus Houghton.
At the other end Michael Coyle fired just over the bar before Stephen McHugh failed to hit the target when well placed. Aileach responded and Gareth McGlynn beat two defenders but fired over from the edge of the box.
On the stroke of half time Aileach spurned a good chance when Dermot Doherty drifted in behind the home defence but fired wide from a good position.
The home side spurned a great chance after the break when an excellent Aaron McColgan free kick found Kevin O’Loughlin who flashed a header just wide.
Aileach hit back and took the lead on 56 minutes when the home defence failed to clear and in the ensuing scramble Gavin Doherty forced the ball home from close range.
They almost added a second but Ronan Coyle flashed a volley wide when well placed. The Hearts had a great chance to get back on terms when McHugh found himself in the clear but fired straight at Peter Devlin in the Aileach goal.
Aileach upped the tempo and substitute Anthony Doherty fired narrowly wide before Darren McMonagle had a shot saved by Houghton.
Buncrana were then dealt a blow when Brendan Halpin picked up a second caution and was red carded. Buncrana huffed and puffed but failed to force the tie into extra time.