Clare star Tony Kelly gave a five-star display when helping Limerick IT set up a quarter-final showdown with their city neighbours.
Kelly finished with 1-8 after a dramatic contest in which GMIT were reduced to 14 players midway through the first half when Gerry Hennelly was shown a straight red card for a foul on Cian Nolan.
The dismissal was costly as GMIT were only a point behind after 44 minutes when they were awarded a penalty. However, Shane Moloney's low shot was superbly saved by Aaron Murphy.
Limerick IT gained control after that, with practically everything being orchestrated by Kelly, who scored a few superb points from play, before blasting home a penalty seven minutes from the end to put the issue beyond doubt.
Scorers – LIT: T Kelly 1-8 (1-0 pen, 6fs), C McInerney 0-3, S O'Brien 0-2, S McGrath 0-1. GMIT: S Moloney 1-5 (1-2fs), P Flanagan 1-0.
Limerick IT – A Murphy; S O'Gorman, M Minihan, C Nolan; P Flaherty, B O'Connell, E Boyce; S O'Brien, T Kelly; P Begley, M Gennary, P Ivors; S McGrath, C McInerney, O Hickey. Subs: P Robinson for Ivors (43), D Whelan for Hickey (45), G Guilfoyle for McGrath (45).
GMIT – J Egan; C O'Donnell, T Kenny, P Fox; K Lane, G Grealish, N Keary; J Kilkenny, G Brennan; D McGreal, P Hoban, C O'Donnell; G Hennelly, S Moloney, P Flanagan. Subs: S Lawless for Brennan (40), Brennan for McGreal (57).
Ref – J O'Brien (Tipperary).