Marist College from Athlone retained their title with a deserved victory at the Sportsground in Galway.
Current Connacht star Robbie Henshaw inspired them to victory last year when they won only their second ever crown, but this time round they had a much more balanced side and played some good rugby.
However, they were pushed all the way by Garbally, winners of the competition a record 44 times, but whose only success in the past 12 years came in 2007.
The losers tried to get a foothold early in the game, but, while they enjoyed good possession, they were unable to get a score on the board against the breeze.
Instead, it was the champions who hit the front when out-half Barry Goode made no mistake with a penalty from the left after 17 minutes.
And the Athlone side struck a telling blow after 26 minutes when a fleeting left-to-right move, in which centres Sean Dempsey and Cormac Langdon made significant ground, ended with Harry Hughes scoring in the corner.
Goode landed a conversion from the touchline and he tacked on another penalty before the break to leave the holders with a 13-0 interval lead. Scrum-half Sean Horan pulled back a penalty for Garbally from the right five minutes after the restart.
But the Marist response was immediate, with John Gormley making the hard yards. Another penalty was conceded and Goode converted.
A Horan penalty after 44 minutes kept the Ballinasloe college in touch and a sustained bout of pressure on the Marist line ended with Garbally captain Jack Codyre crossing for a try.
Horan was off target with the conversion to leave the score at 16-11.
The Marist response was again decisive with full-back Eoghan O'Reilly countering from deep and, when he was held up, he had left winger Robbie McMicken in support to dash over.
Goode again added the points to make it 23-11 and there was no way back for Garbally as Marist defended well to claim the title on the 100-year anniversary of the competition.
Marist College – E O'Reilly; H Hughes, S Dempsey, C Langdon (T Finucane 67), R McMicken; B Goode (C McMicken 67), R Ashe; J Gormley, C McGrath (C Walshe 70), J O'Meara (S Meunargia 63); C O'Brien, J Flynn; C White (R Flanagan 70), B Cooper (C Cooper 65), E Galvin.
Garbally College – A Mannion (C Dooley 68); R Kelly, C Barrett, I Duffy, S Tierney; S Keller, S Horan; D Walshe (S Lyons 65), P Gilsenan, D O'Hara; P Claffey, S Holland; D Connolly (B Wilmore 70), D Curley, J Codyre.
Ref – J Langan.