Mayo's Peadar Gardiner, Alan Dillon and Ronan Rochford inspired NUI Galway to an impressive victory in Ballinode.
Man of the match Gardiner scored 1-3, while Dillon hit three points and Rochford was outstanding at corner-back in the 10-point win.
The scoreline was harsh on the hosts, though, who trailed by just a point at the break, 0-8 to 0-7.
The 35th-minute sending-off of centre half-forward Eugene Keating for an off-the-ball incident badly affected Sligo, who conceded three second-half goals.
IT Sligo opened the scoring through Adrian Croal, but NUIG hit the next five scores.
Back came the Sligo college with scores from Keating, Martin Brady, David Givney and Kenneth Sweeney to leave the gap at just a point.
Jason Doherty smacked another goal attempt off an upright, but managed to point the rebound.
Paul Garvey's pointed free at the other end kept it tight, but Keating's red card a minute later cost IT Sligo dearly, with Fiacra Deasmhunhaigh and Doherty claiming goals inside the 10 minutes that followed.
Scorers -- NUIG: P Gardiner: 1-3, F Deasmhunhaigh, J Doherty 1-1 each, A Dillon 0-3 (1f), N Douglas 0-2, A Mullin 0-1. IT Sligo: E Keating, K Sweeney (1f) 0-2 each, M Brady, D Givney, A Faherty (1 '45'), P Garvey, S Coen (1f), A Croal 0-1 each.
NUIG -- N King; C McDonald, K O'Connor, R Rochford; P Gardiner, C Conroy, J Moore; S Gilmartin (capt), D Coroon; M McHugh, A Dillon, A Mullin; N Douglas, F Deasmhunhaigh, J Doherty. Subs: B Geraghty for McHugh (35), K Conlon (Galway) for Conroy (35), S McHale for Moore (52), K Conlon (Offaly) for Mullin (49).
IT Sligo -- A Faherty (capt); D Reynolds, P Gleeson, P Maguire; G Gaughan, M Leddy, D Daly; T Parsons, D Givney; M Brady, E Keating, P Garvey; A Croal, K Sweeney, D Cummins. Subs: S Coen for Garvey (36), S Mannion for Gaughan (48), P Kelly for Gleeson (48).
Ref -- D Fahy (Longford).