But the former champions must beat Limerick IT in their final game to progress to the last eight after losing to Dublin City University in the first round.
A pair of first half goals from Shane Ryan helped WIT lead 2-6 to 1-4 at the break, before Joe O’Connor and Andrew Joyce added second half strikes.
Cian O’Sullivan hit 1-6 for Trinity, including a long-range goal from a sideline cut that deceived Mark Fanning, and six pointed frees.
L McGrath 0-7 (5f), S Ryan 2-0, A Joyce & J O’Connor 1-0 each, T Fox & S McNulty 0-2 each, J O’Dwyer, P Walsh, C Lyons & A Gleeson (f) 0-1 each.
C O’Sullivan 1-6 (1-0 sl, 0-6f), E Kelly & C O’Carroll 0-1 each.
M Fanning (Wexford); W Hahessy (Waterford), J Henderson (Kilkenny), S Donohoe (Wexford); C O’Brien (Cork), J O’Dwyer (Tipperary), T Fox (Tipperary); C Lyons (Waterford), P Walsh (Waterford); S Murphy (Kilkenny), A Gleeson (Waterford), S McNulty (Waterford); S Ryan (Waterford), G Lane (Cork), L McGrath (Tipperary).
J O’Connor (Offaly) for Lane (24), A Joyce (Cork) for Murphy (42), C Neven (Galway) for Ryan (58).
E Skelly; J O’Neill, D O’Donoghue (Galway), C Keating (Tipperary); F O’Riain Broin, M Malone (Clare), D Williams; C O Dulaing, C O’Sullivan; D Butler, N Redmond (Wexford), C O’Riain Broin; E Kelly (Wexford), C O’Carroll (Kilkenny), S Ryan (Dublin).
S O’Connor (Cork) for Williams (42).
J Keenan (Wicklow).