The holders emerged victorious thanks to three well-executed tries, two of which arrived in the opening quarter from left winger James Beary and lock Mike O’Donnell, while the winners also crossed the whitewash in the final minute of the game through right winger Jack Hogan.
In between Crescent College dominated much of the play, but a combination of gritty defence from their opponents and a lack of composure, including several handling errors, ensured the outcome remained in some doubt.
Both sides deserve credit for adopting such an entertaining and expansive approach on a near-perfect day for rugby.
Crescent made a dream start when, following a concerted period of early pressure, O’Donnell powered his way over the line from close range. Centre Greg O’Shea duly added the conversion.
Glenstal, surprise winners over CBC in the previous round, hit back quickly, however, with two quick-fire penalty goals through centre Kevin O’Keeffe.
Crucially, the holders breached the Glenstal defence mid-way through the half when winger James Beary crossed for a second try following an impressive back-line move. Crescent maintained that 12-6 advantage until the half-time break.
With just six points between the sides through the third quarter, the tie remained very much alive.
While the vast majority of the second period was played inside the Glenstal half, Crescent lacked the cutting edge necessary to grab a vital third try.
The holders did some admirable patience and finally succeeded in putting some daylight between the sides in the 47th minute, when out-half Gearoid Lyons landed a terrific penalty goal.
The score left nine points between the teams and ensured Crescent now held a two-score advantage.
The holders finished the game on a high when full-back Jason O’Sullivan put winger Jack Hogan over in the right corner to score. Lyons duly added the extras to leave Crescent looking forward to a final date with city rivals Ard Scoil Rís.
Scorers for Crescent: M O’Donnell, J Beary, J Hogan try each, G Lyons pen, con, G O’Shea con.
Scorers for Glenstal: K O’Keeffe 2 pens.
J O’Sullivan; J Hogan, G O’Shea, JJ O’Neill, J Beary; G Lyons (Capt), E Barry; J Tuohy, C Rea, L McMahon; M O’Donnell, J Kavanagh; R Noone, J Green, C Blake.
Replacements: T Moloney for Beary (47), M O’Connor for McMahon (56)
C Healy; M Boland, K O’Keeffe (Capt), H Connors, M Hogan; O Bradley, R Hogan; A Plettenberg, J Healy, J Murphy; B Clancy, N Mulvihill; K Glynn, G O’Hara, J Boland .
Replacements: H Healy for Boland (58).
Referee: F Butler (MAR).