Dungarvan — known as Coláiste na nDéise last season — scored a six-point victory over their Limerick opponents, who trailed by nine points at half-time.
Patrick Curran’s first-half goal helped to open up a 1-10 to 0-4 interval lead for Dungarvan Colleges, who played with the wind from the throw-in.
But Doon CBS, inspired by Patrick Ryan, came roaring back into contention and trailed by a point (1-10 to 1-11) with 10 minutes left.
Ryan’s 41st-minute goal kickstarted the revival but Dungarvan responded with two late goals to seal victory.
Both were scored by Ryan Donnelly — one of eight players lining out from the start who featured against Nenagh CBS in last February’s Harty Cup decider.
Dungarvan were outscored by 2-3 to 1-9 in the second half but Donnelly popped up with a deadly brace to give his side an ideal start in what promises to be a competitive group.
Scorers for Doon: P Ryan 1-3, B Murphy 0-4 (3f), D Coleman 0-4 (2f, 1 sl), D O’Donovan 0-2.
Scorers for Dungarvan Colleges: R Donnelly 2-2, P Curran 1-5 (0-5f), C Dunford 0-3 C Breathnach, T Burke & Ml Harney 0-1 each.
DOON CBS: C Ryan; F O’Grady, R English, T Hayes; P Cummins, S Ryan, S O’Connell; D O’Donovan, D Coleman; M Dee, P Ryan, D Orr; B Murphy, R Ryan, K Stapleton.
Subs: B McCarthy for Orr (39), D Cosgrave for Stapleton (48), A Coleman for R Ryan (58).
DUNGARVAN COLLEGES: L Power; K Looby, B Looby, M Cronin, C Breathnach, T Devine, T Burke; C Dunford, C Curran; E Crotty, Ml Harney, R Donnelly; D Gartland, K Daly, P Curran.
Subs: A Donnelly for Crotty (51), S Daly for Gartland (53), R Browne for Dunford (58).
Referee: F Horgan (Knockavilla Donaskeigh Kickhams, Tipperary).