Fermanagh had coasted into a 0-6 to 0-0 lead in the opening 20 minutes, Seamie Quigley hitting five points but St Mary’s goaled through Conor McCann after 23 minutes to get them going.
Former Tyrone minor Thomas Canavan then scored two brilliant points from play and Armagh panellist Aidan Forker was also on target as the visitors led 1-5 to 0-6 at the break.
Canavan, a nephew of former Fermanagh boss Peter, had a starring role for the students and he converted a free before drilling St Mary’s second goal after 50 minutes.
Seamie Quigley hit back with a penalty for Fermanagh which resulted in the only black card of the game.
Scorers for Fermanagh: Seamie Quigley 1-7 (1-0 pen, 0-2f), R Jones, Sean Quigley, C Jones 0-1 each
Scorers for St Mary’s: T Canavan 1-3 (1f), C McCann 1-0, A McGarrity 1-0, C McMahon, P Carragher, R O’Callaghan, A Forker, B Hasson 0-1 each
FERMANAGH: C Snow; J Woods, N Cassidy, M O’Brien; D McCusker, B Mulrone, C Quigley; R Jones, S McElrone; T Daly, N McIlroy, C Jones; R Ormsby, Seamie Quigley P McCusker
Subs: Sean Quigley for N McElroy (43), J love for C Jones (43), M McAleer for Daly (59), A Boyle for P McCusker (65)
ST MARY’S: D McAnenly; A Maguire, N Donnelly, M Murray; C McCann, R Loughran, C McMahon; P Carragher, E Bradley; R O’Callaghan, A Forker, J Duffy; B O’Hagan, B Hasson, T Canavan
Subs: R Sexton for Bradley (44), R Johnston for McCann (44), A McGarrity for O’Hagan (51), K McKernan for Donnelly (58), T McCaffrey for Duffy (67)
Referee: P Hughes (Armagh)