The eight-time champions recorded consecutive successes themselves in 2010 and 2011, and having fallen short two years ago against St Michael’s, they will be eager to reclaim the Leinster Schools’ crown.
Andrew’s had been rampant during their 47-3 demolition of Gonzaga College at the quarter-final stage, but they were permanently camped inside their own 22 during the first-quarter.
Clongowes full-back Alan Hughes broke the deadlock with a 15th minute penalty, but it was a credit to Andrew’s that their diligent, and at times heroic, defensive work had snuffed out their north Kildare counterparts on a number of occasions.
Indeed, having avoided the concession of an early try, Andrew’s pounced for an opening five-pointer on 24 minutes, when full-back Andrew Fogarty yielded a try from his own quick line-out, via neat link-up play with Jordan Larmour.
Jack Balbirnie’s bonus strike was emphatically secured, helping the underdogs into a surprising 7-3 advantage.
With their passionate supporters cheering them off at the mid-way point, they were 35 minutes away from a first final appearance in 92 years.
Wood had been frustrated by their plucky opponents on a number of occasions, but they finally crossed the whitewash through powerhouse flanker Josh Pim four minutes after the restart.
There was a sense that this would be the defining moment in the tie, and with Hughes adding five points to his tally, Clongowes were finally in control of their destiny.
The Andrew’s challenge grew in prominence again as the final-quarter beckoned, but Clongowes were alert to the danger and a fabulous individual try down the left-wing by Cian O’Donoghue seven minutes from time placed the outcome beyond any doubt.
Number 8 Stephen McVeigh added a converted score for the victors in stoppage-time after picking up a loose ball from a scrum, and even though Andrew’s registered a deserved consolation try through lock Jonny Guy, it wasn’t enough to spoil the Clongowes party.
Scorers for Clongowes Wood College: J Pim, C O’Donoghue, S McVeigh try each, A Hughes 2 pens, 3 cons.
Scorers for St Andrew’s College: A Fogarty, J Guy try each, J Balbirnie con.
CLONGOWES WOOD COLLEGE: A Hughes; J Lappin, C Mulcahy, C Burke, C O’Donoghue; F Cleary, R Osborne; N Rinklin, J Molony, D O’Leary; C Gleeson, J Kennedy; W Connors, J Pim, S McVeigh.
Replacements: J Lyons for Molony (28-31 & 73), J Inglis for O’Leary (42), J Glynn for Osborne (67), D Kiely for Kennedy (69), C Godson for Rinklin, E Tyrrell for Gleeson, C Gillick for Pim, C Murray for Cleary (all 73).
ST ANDREW’S COLLEGE: A Fogarty; J Larmour, G Fearon, M Kirk, G Beere; J Balbirnie, D Joyce; A Porter, A Brady, D Higgins; A Guy, J Guy; R Bradley, B Ingram, G Jones.
Replacements: F Irwin-O’Hara for Brady (49), S Hayes for Bradley, K Jordan for Fogarty (both 52), D Hide for Beere (58), A Waller for A Guy (61).
Referee: S Gallagher (LRR).