Moved when there was just 15 minutes to go, the Erin's Own man rattled the LIT net with his first touch to tie the game for the fourth time. Seconds earlier Iarla Tannian blasted home a goal for the defending champions to put the home side in front.
After Tannian's goal, LIT had scored 1-3 without reply looked destined to stay in the title race, but O'Connor won the puck out before drilling the sliothar into the Limerick net and he quickly added a point to rock the defending champions.
This was a magnificent contest, played with the kind of passion you only get at this level. With UCC hosting the concluding stages, the weekend after next, they were desperate to be involved, and, they deserved their victory.
Team coach Alan Browne, former Cork senior captain, said: "With so many inter-county players involved with both teams and followers on the sideline so vocal, bragging rights were very important also. That's what Fitzgibbon hurling is all about."
UCC had many stars. The Kilkenny duo of John Tennyson and Brian Cody were magnificent in defence, Tom Kenny's pace at midfield was significant, while up front, Ronan Conway, Mark O'Connor and Michael Rice caused endless problems for the LIT defence.
Eoin Kelly was a huge loss for the champions, while Galway senior Niall Healy struggled with a hamstring injury and was eventually taken off. LIT had problems in attack, where only Iarla Tannian and Bernard Gaffney had the physical strength to trouble the teak-tough UCC backs.
The home side, aided by the strong wind in the first half, threw the gauntlet down to the Cork students and were 0-3 to nil ahead after five minutes, Gaffney scored two points, and LIT should have had a goal after Donal O'Reilly broke through, but his shot failed and the chance was lost.
In the eighth minute, UCC's Ronan Conway ran on to Kevin Hartnett's long clearance before rifling home a splendid goal that tied the match.
The exchanges were razor keen with little or nothing between the sides, but James Fitzpatrick's excellent free taking helped UCC to an interval lead of 1-6 to 0-6, after he converted three frees in a row.
Like true champions LIT were not going to give up their title easily, and with Iarla Tannian playing the proverbial blinder, on the 40, they were level by the 37th minute after three points in a row. As UCC struggled to cope with their ferocity, the home side went ahead after Tannian first-timed the sliothar to the net to make it 1-9 to 1-6.
In the next 30 seconds, the complexion of the match changed as Mark O'Connor tied the game with his goal. Despite the best efforts of Tannian and Shane McGrath, UCC finished strongly to book their place in the concluding stages.
: UCC: M. O'Connor 1-3; J. Fitzpatrick 0-4 (frees); R. Conway 1-0; P. Murray, S. O'Sullivan (free), T. Kenny 0-1 each. LIT: I. Tannian 1-2; B. Gaffney, D. O'Reilly, N. Healy (frees), F. Flynn (0-1 free, 0-1 65) 0-2 each; C. Earlie 0-1 (free).
: E. Martin; J. Tennyson, D. McSweeney, D. Cody; S. O'Neill, P. Murray, K. Hartnett; S. O'Sullivan, T. Kenny; R. Conway, M. Rice, E. Hanley; J. Fitzpatrick, M. O'Connor, P. O'Brien.
: G. O'Connor for O'Brien; M. Harrington for Hanley; Stephen Cronin for Paul Murray.
: S. Hawes; C. Mahoney, J. Coen, E. Collins; D. Morrissey, F. Flynn, M. O'Brien; S. McGrath, J. Clancy; J. McInerney, I. Tannian, S. Tierney; B. Gaffney, D. O'Reilly, N. Healy.
: J. Skehill for Hawes; C. Earlie for Healy.
: J. McDonnell (Tipperary).
: Friday, March 3: UCC v UCD; NUIG v WIT.