The victory came off the back of two quick-fire converted tries late in the first half to break Ardscoil’s dogged challenge, in front of 6,000 people.
A third try midway through the second half, following a sustained period of territorial dominance that yielded nothing for the losers, made the game safe for a team that had more firepower and experience.
Crescent made most of the running but also most of the mistakes in the opening quarter, turning over four times as they attempted to break down a determined Ardscoil Rís defence.
The first real scoring chance did fall to them, however, when Fionn McGibney was given a penalty opportunity 40 metres out. The out-half struck it well but short of the target.
Throughout that disappointing first half, there were isolated inspirational moments, with Crescent’s centre pairing Will Leonard and JJ O’Neill and Ardscoil captain Stephen Fitzgerald providing the best of them.
That is until Crescent skipper Cormac Blake finally broke the deadlock in the 27th minute, with a powerful surge through the centre of the Ardscoil defence from 25 metres out. He was hand-tripped five out but managed to squeeze over the line for a try that McGibney converted. It mattered little that Ardscoil had appealed for a knock-on in the build up.
There was no such doubt about the second try in the 35th minute, full-back Dylan Sheehan brilliantly weaving his way through the Ardscoil defence before touching down.
McGibney added the conversion to secure a 14-0 lead interval lead.
Ardscoil out-half David O’Mahony missed a penalty a minute into the second half as his side tried to get back into the contest. Two blocks had Crescent scrambling to hold onto their lead, particularly during the spell when Robbie Scott was in the bin, for killing the ball in a ruck.
Crescent survived brilliantly and the pressure was eased when Ardscoil flanker Jerry McCabe was sin-binned for another technical foul.
Crescent took full advantage of the extra man and winger Jason O’Sullivan finished off a fine movement to score wide out on the left, with McGibney brilliantly converting for a 21-0 advantage.
Ardscoil were rewarded for their efforts three minutes from the end of normal time when Kelvin Brown got in for a try that O’Mahony converted but it would not be enough.
CRESCENT COLLEGE COMPREHENSIVE: D Sheehan, J O’Sullivan, JJ O’Neill, W Leonard, C Nash, F McGibney, G Fitzgerald, M O’Donnell, C Moloney, L McMahon, R Scott, R Noone, S Fitzgerald, C Blake (captain), J Kavanagh,
Replacements: J Hogan for Nash, E Barry for Fitzgerald (61), C Guerin for Noone (65), J Harrington for O’Neill (68). Temporary, M Rickard for O’Donnell (63).
ARDSCOIL RÍS: S Fitzgerald (captain), B Moriarty, P McNamara, J O’Donnell, L Brock, D O’Mahony, D Scannell, J O’Halloran, S Fenton, T Walsh, D Ryan, P Staff, J Cannon, K Brown, J McCabe.
Replacements: H Bourke for Scannell, Bracken for Walsh, L Whyte for Brock (all 55).
Referee: E. Hogan O’Connell (MAR).