Back in the competition for the first time since 2004, Mary I need a win next week to reach the knockout stages.
In a thrilling contest, a last-gasp goal by Brian O'Halloran earned the Limerick college a draw to add to their point won in their previous game.
At half-time, Mary I led 0-10 to 1-6, with Brian Hartnett getting the goal after a pass by Dan McCormack.
There was an explosive start to the second half with a mass brawl that resulted in three players being shown yellow cards, two from Mary I.
Mary I stretched their lead through John Conlon and Declan Hannon. Dan McCormack and a Hartnett free left only one between them before Conlon pointed.
It was level after Paul Haughney and William Egan struck superb points for UCC.
Conor Lehan and two more frees by Hartnett looked to have won it for the Cork side, until a cracking shot by Hannon in the final seconds was only partially blocked and Brian O'Halloran fired home to salvage a draw.
Scorers – Mary Immaculate: J Conlon 0-8 (8f), B O'Halloran 1-0, D Hannon (2f), L Farrell 0-2 each, J Wall 0-1. UCC: B Hartnett 1-6 (4f), P Haughney 0-2, B Lawton, B Murray, D McCormack, C Lehane, W Egan 0-1 each.
Mary Immaculate – S Nolan; C Fennessy, R O'Donnell, E Hogan; J Wall, D Hannon, N O'Meara; L Considine, K Fitzgerald ; C Galvin, W Hickey, S Curran; B O'Halloran, J Conlon, L O'Farrell. Subs: M O'Connell for Fitzgerald (47), D O'Carroll for Hickey (50).
UCC – D McCarthy; K Ryan, D Glynn, K Murphy; W Egan, P Prendergast, J Barry; P Haughney; B Lawton; C Murphy, D McCormack, B Hartnett; B O'Sullivan, B Murray, C Lehane. Subs: S Harnedy for Murray (45), M Sugrue for McCormack (56).
Ref – A Kelly (Galway).