The visitors took early command on the astroturf surface and, showing deadly accuracy, stormed into a 0-6 to 0-1 lead by the ninth minute.
With Limerick senior players Cian Lynch and Aaron Gillane prominent, Mary I led 0-11 to 0-6 after 20 minutes before a fine Carlow move saw saw Kilkenny senior panellist Ritchie Leahy crash home the game’s only goal.
By half-time, having played with the wind, Mary I led by a point, 0-14 to 1-10.
IT Carlow lost right-corner-forward Mark Russell to a straight red card for a striking offence in the early minutes of the second half.
However, their defence held firm for the remainder of the game, with James Doyle and Michael Harney outstanding, while they benefitted from the magnificent long-range free-taking of goalkeeper Enda Rowland of Laois, who landed three monster dead-ball efforts.
IT Carlow took the lead for the first time following an outstanding passage of play involving James Doyle and Waterford’s Colin Dunford, who placed midfield colleague Leahy for the lead point (1-14 to 0-16) as the game entered the final quarter.
With the wind in their sails and at their backs, IT Carlow carved out a four-point lead on two occasions and held on to record a deserved victory.
M Kavanagh (0-9, 7 frees, 1 65); C Dwyer (0-6); R Leahy (1-1); E Rowland (0-3 frees); C Dunford, S Downey, C Dunbar (0-1 each).
A Gillane (0-7, 6 frees, 1 65); C Lynch (0-5); E Cahill (0-3 frees); L Meade (0-2); S Taylor, T Grimes, G Cooney, T O’Mahony, B Corry (0-1 each).
E Rowland; S Reck, K Hannafin, R Brown; M Redmond, J Doyle, M Harney; C Dunford, R Leahy; S Downey, M Kavanagh, C Dwyer; M Russell, J Fagan, C Dunbar.
E Cahill; C McCullagh, D Prendergast, C Steapleton; D Browne, S Taylor, T Grimes; J Mackey, L Meade; A Gillane, C Lynch, P Ryan; G Cooney, T O’Mahony, B Corry. Subs: C Guilfoyle for Corry (45); N Heffernan for Ryan (51).
J Keenan (Wicklow).