Rosie Carrigan's corner rebound kept UCD's dream of retaining the ESB Irish Senior Cup alive as she scored the decisive goal to beat Cork Harlequins at Belfield.
She pounced on a 14th minute corner rebound for the game's only goal. Laura Wilson bashed a superb strike which dinged off the inside of Amy O'Neill's left-hand post only to fall for Carrigan to neatly push home.
From then on, Cork Harlequins generally showed plenty of menace leading up to the 25 but were scarcely able threaten once inside the danger zone.
Karen Bateman did net only for her effort to be brought back for an earlier penalty corner infringement but that was the extent of goal-mouth incident for Quins as UCD defended their circle immaculately.
The win sets up a repeat of last year's famous second round win against Loreto on penalty strokes. The Beaufort side struck late to ease away from Pembroke in a tight battle.
Their sharpness in either circle was the difference in a flowing game. Ali Meeke and Hannah Matthews had given Loreto a very early lead but Sinead Loughran pulled one back on the stroke of half-time to give Pembroke a lifeline.
Chances a plenty but a second goal from Meeke and one from Nicci Daly in the last six minutes gave the scoreline a more comfortable look.
Railway Union have set up an enticing semi-final draw against Pegasus after both emerged from extremely tight fixtures in Ulster, beating Ards and Ballymoney respectively.
Patricia O'Dwyer bagged a 31st minute strike to see Railway through as they dominated the first half despite struggling on the slower surface in Ards. Emma Smyth stood out, though the second half was a tense affair with neither side able to settle into much of a rhythm.
Suzanne Beaney's hat-trick meant Pegasus' hopes of avenging last year's final defeat to UCD remain alive.
She scored the golden goal which divided themselves and Ballymoney having earlier cancelled out goals from Susie Martin and Irish star Bridget Cleland for 2-2 at the end of full-time.
ESB Irish Senior Cup - semi-final draw
UCD vs Loreto; Pegasus vs Railway Union
ESB Irish Hockey Challenge - first round:
Dungarvan 0 Monkstown 2 (Courtney Waktins, Sarah Murray); Derg Valley 1 (A Sproule) Greenfields II 0 aet
Leinster Division One: Hermes 1 (Aoife Harte) Bray 0
Hermes closed the gap on the leading pair in the only division one on Saturday, eventually breaking the deadlock 15 minutes from time against a Bray side who once more showed their solid nature. Mary Goode was to the fore to deny multiple waves of attacks but a clever corner, Jenny Burke hitting for Aoife Harte's deflection, provided the only goal of the game. The win moves Hermes within two points of second placed Railway Union.