Free-taker Shane Caulfield pointed the way as Mercy Colleges -- an amalg-amation of schools from Loughrea and Woodford in Co Galway -- powered their way into the final.
Mercy, coached by Galway senior selector John Hardiman, trailed by 2-4 to 0-5 at the break after goals from Adrian Tuohy and Paddy O'Connor for south Galway side Gort.
But seven frees from Caulfield, and late goals from Jason Flynn and Stephen Keon, sent Mercy into the provincial final, where they will meet holders Presentation College, Athenry.
In an entertaining encounter, Mercy held a healthy advantage until injury-time, when Keon raced through and kicked to the net to seal victory.
Gerard O'Donoghue responded with an even later goal, but it was scant consolation for Gort.
Scorers -- Mercy Colleges: S Caulfield 0-7 (7f), J Flynn 1-3 (2f), S Keon 1-0, C Quinn 0-2, S Lawless 0-1. Gort: K Lane 0-4 (3f), A Tuohy 1-1, P O'Connor, G O'Donoghue 1-0 each, E Linnane, B Murtagh 0-1 each.
Mercy Colleges -- L Uniacke; S Moloney, G Rooney, D McManus; C Nevin, P Hoban, D Morgan; S Caulfield, P English; C Quinn, J Flynn, K Cormican; D Madden, S Lawless, S Keon. Subs: D Sweeney for Lawless (24), C Whelan for Sweeney (60), P Burke for Madden (60).
Gort CS -- M Kelly; K Murphy, A Larkin, T Reynolds; S Collins, M Glynn, S Coen; R Burke, B Murtagh; P Lally, K Lane, E Linnane; G O'Donoghue, P O'Connor, A Tuohy. Subs: S Cooney for Lally (45), D Roche for Collins (48), A Fahy for O'Connor (54).
Ref -- J Larkin (Galway).