Conor Cox took the scoring honours with six points, but a resolute defensive effort was just as crucial to UCC's last-eight victory over St Mary's at the Ballykelly pitch in Co Kildare.
Cox finished with six points, split evenly from play and frees, and was a constant menace.
Defenders Peter Crowley and Eoin O'Mahony had huge games too, as they managed to completely shackle the dangerous-looking two-man full-forward line of Tyrone star Peter Harte and Armagh's Aidan Forker.
Harte was ultimately forced to roam in a bid to have more of an influence on proceedings, but he found no more leeway from Jamie O'Sullivan in a sector of the field in which Peter Acheson, JP Spillane and Kevin O'Driscoll were tireless workers.
The Skull and Crossbones got off to a fine start with points from O'Driscoll and Cox (free) inside five minutes.
Tyrone goalkeeper Niall Morgan advanced to get St Mary's off the mark with a wonderfully-struck '45' into a diagonal breeze and it was nip-and-tuck from there to the end of the half.
Conor Clarke helped St Mary's gain a foothold around the middle with some wonderful catches and a Thomas Canavan free brought the sides level at the end of the first quarter.
Cox and Canavan exchanged frees – Canavan's was the second one to be moved forward by Fergal Barry due to dissent by a UCC player – before Cox struck his first from play to put his side 0-5 to 0-4 up at half-time.
The Leesiders upped their intensity significantly after the resumption and were the better side throughout the second half. They were three points clear when Benny Herron burst through and finished expertly for a treasured St Mary's goal.
Undeterred, UCC continued to defend stoutly and break at pace. Their response was impressive and, fittingly, it was Crowley who advanced to restore their advantage.
Substitute Luke Connolly, Eoin Buckley (free), Cox (free) and O'Driscoll gave them vital breathing space and were it not for a splendid stop by Morgan from Gavin O'Grady, who had made a stupendous catch, the final margin would have been greater.
Scorers – UCC: C Cox 0-6 (3f), E Buckley 0-3 (2f), K O'Driscoll 0-2, P Crowley, L Connolly 0-1 each. St Mary's: B Herron 1-1, T Canavan 0-2 (2f), N Morgan ('45'), M Murray, J Johnstone 0-1 each.
UCC – S Mellett; P Galvin, E O'Mahony, J O'Sullivan; P Crowley, N Daly, T Clancy; D O'Sullivan, P Acheson; K O'Driscoll, B Coughlan, JB Spillane; E Buckley C Cox, C McSweeney. Subs: G O'Grady for McSweeney (h-t), L Connolly for O'Sullivan (49)
St Mary's – N Morgan; M Murray, N Donnelly, C O'Hara; D McCusker, N McParland, B Doyle; C Clarke, D McBride; N Sludden, B Herron, A Forker; R Sexton, P Harte, T Canavan. Subs: J Johnstone for Canavan (50); M Stevenson for Sexton (51).
Ref – F Barry (Kildare)