Extra-time was beckoning, with the sides locked at 1-9 to 2-6. But in an effort to avoid another 20 minutes' play, UUJ had left a huge hole in their own defence as they moved forward in search of a winner.
However, their passing movement broke down and the ball was swept upfield to Joe Sheridan, who touched it on to the unmarked Hanley. Ronan Gallagher came off his goal-line to avert the danger but Hanley cooly slipped the ball over the bar for the winning score.
On the balance of play UCD deserved it, having they lost a two-point lead at the threequarter stage to a marvellous Enda McGinley goal. But they showed commendable heart in coming back to take the spoils.
The opening half was a very dour affair, with both sides not prepared to take any risks. Consequently, there was little fluency in the play and scores were at a premium.
The sides were level at 0-4 apiece after 25 minutes. However in the last five minutes the game finally opened up, and a Paddy Bradley goal helped UUJ to an interval lead of 1-5 to 0-5, with the promise of better things to come.
And the fair sized crowd wasn't disappointed. Both sides went all out for victory and the net result was a game of outstanding quality. Mistakes were made but the pace and passion of the football was thrilling.
And it was from a UUJ mistake that UCD got their goal.
A pass by Barry Shannon never found its intended target, John Hanley nipped in to send Alan Brogan through on goal and he made no mistake from close range.
UCD were full of running at this point with Stephen Lucey, Darren Magee and Barry Cahill in the thick of the action, but just when it looked as if the exertions of the previous day had taken their toll on Jordanstown, they struck back with a vengeance.
In a sweeping movement from their own defence, Enda McGinley rattled the UCD net with a powerful shot and he followed it with a point to suggest they had sufficient in the tank to go on and win it.
It wasn't to be, however, as a clearly fitter UCD side began to tighten the screw.
It took a marvellous save by Ronan Gallagher to deny the impressive Peter Lawlor a goal, before points by Lawless and Liam Ó hEineachain tied the game for the fourth and final time with seven minutes to go.
Surprisingly McGinley's point in the 43rd minute was to be UUJ's last score of the afternoon and while they threw everything at UCD in those hectic last few minutes, there was no way through.
In the end it was left to Hanley to set up a mouth-watering final with NUIG at Pairc Uí Rinn. Throw-in is at 4.15.
Scorers UCD: P. Lawlor 0-6 (0-4 frees); A. Brogan 1-1; J. Hanley 0-2; L. Ó h-Eineacháin 0-1.
UJ: E. McGinley 1-1; P. Bradley 1-0; M. Walsh (free); S. Cavanagh, B. Shannon, S. Kearney, P. Loughren 0-1 each.
UCD: G. Magill; D. O'Donoghue, C. Evans, P. Griffin; B. Cahill, S. Lucey, R. Kelly; D. Magee, C. Murphy; J. Hanley, B. Ó hAinneadh, L. Ó hEineacháin; A. Brogan, R. Ronaghan, P. Lawless.
Subs. P. Curran for Ó hAinneadh; T. O'Connor for Kelly; J. Sheridan for Evans.
UUJ: R. Gallagher; T. Earley, C. McGinley, C. McCrory; P. O'Kane, L. Doyle, B. Shannon; P. Loughren, P. Rouse; S. Cavanagh, M. Walsh, M. O'Rourke; P. Bradley, E. McGinley, S. Kearney.
Referee, P. Russell (Tipperary).