A try nine minutes from time by flank forward David Cox gave Carlow a hard earned win at Lakelands Park on Saturday and moved them to second in the table, trailing Shannon only on points difference.
It was a victory primarily for Carlow's powerful pack in a match that produced little in the way of fireworks.
Terenure had the better of the first half and turned over leading 8-7 but it could have been more as they spurned some try-scoring chances, notably when wing Matt Dowling lost the ball as he was about to dive over in the corner.
Carlow's points had come from a Mark Buckley interception try, converted by Matthew Waterhouse, while Terenure had a penalty from Richard Governey and a try from hooker Cormac Egan.
Waterhouse edged Carlow in front with a penalty shortly after the break before Cox got the decisive score off a lineout drive. Waterhouse and Governey exchanged penalties in the closing minutes.
TERENURE COLLEGE: S Cullen; M Dowling, M Smyth, J Sullivan, J Treacy; R Governey, K Putt; J Nolan, C Egan, S Barretto, M Quinn, D Quinn, P O'Malley, D Blaney, B Kavanagh. Replacements: D McInerney for Treacy (71 mins), G Deans for Nolan (73 mins), B Blaney for Egan (80 mins), N Allica for M Quinn (56 mins), A Ryan for Kavanagh (57 mins).
CO CARLOW: M Spiller; M Buckley, M Waterhouse, R Armstrong, I Dwyer; B Murphy, R Jones; P Brennan, C Gee, L Hannon, L O'Beirne, W Whitten, D cox, A Melville, D Hyland. Replacements: C Blanchfield for Armstrong (66 mins), J Hannon for Gee (54 mins), M Corrigan for L Hannon (52 mins), P Holden for O'Beirne (45 mins), B Baggott for Hyland (45 mins).
Referee: D Tyndall (Leinster).