NOEL McGrath bagged 12 points at Belfield as UCD fought back to book their place in the semi-finals.
Nicky English's side trailed by three points at the break, but with the aid of a strong wind in the second half, managed to overcome the visitors in a fiercely contested battle.
UL took an early lead, scoring three points without reply in the first five minutes, before Tipperary star McGrath got UCD's first score. However, UL continued to have the upper hand as they raced into a 0-6 to 0-1 lead.
The game burst into life after 15 minutes when the home side's Jack Guiney calmly dispatched a low drive into the bottom corner of the net to draw the sides level.
UCD took the lead for the first time when Patrick Murphy finished off a flowing move with a well-taken point.
UL responded well, and heaped pressure on the UCD defence. The champions of two years ago regained the lead with three more frees from Kieran Morris.
With the wind at their backs in the second half, UCD began to get a foothold in the game.
After falling four points behind to an early score from UL's Paul Kelly, they got back to within a point after scores from Cathal Kenny and the outstanding McGrath (2).
The game began to get sloppy as the conditions took their toll, with both sides guilty of conceding soft frees.
It turned into a battle between the two free-takers in the last quarter.
Morris gave UL the lead again with three more points, but UCD captain McGrath booked his side's place in the last four with six points in the final 10 minutes.
It has been six years since UCD last reached the Fitzgibbon Cup final.
Only a semi-final clash with UCC stands in their way of a return to the decider.
SCORERS – UCD: N McGrath 0-12 (11f), J Guiney 1-1, P Murphy, G Sinnott, C Kenny 0-1 each; UL: K Morris 0-10 (7f, 2 '65s'), B Stapleton, P Kelly 0-2 each, M Fennelly, A Ryan, J Glynn 0-1 each.
UCD – B Murphy; J Gannon, R O'Carroll, S Norton; J Douglas, C Ailis, W Phelan; O Gough, N McGrath(capt); J Guiney, P Murphy, G Sinnott; D Fox, C Kenny, B O'Carroll. Subs: M Brennan for Fox, J Mulligan for Ailis.
UL – N McGrath; M Carmody, P Stapleton, P Ryan; G Brennan, C Ryan, J Gallagher; M Fennelly, S Golden; T Heffernan, A Ryan, P Walsh; K Morris, B Stapleton, J Glynn. Subs: P Kelly for Stapleton, D Honan for Glynn, J Fitzgibbon for Heffernan.
REF – B Gavin (Offaly).