Johnny Guy scored the only try of the game to seal St Andrew’s progress to the second round in yesterday’s replay at a very windy Cill Dara.
The winners had the elements in their favour in the opening period and were quickly camped deep in Castleknock territory but some thunderous defence forced three turnovers and they were held at bay.
A good break by Donal McConville helped establish a rare attack and, soon after, the pack forced a penalty.
Prop Geoff Brookes judged his kick brilliantly into the wind to register the opening score.
St Andrew’s responded immediately and Jack Balbirnie, who snatched the draw for his side last week, levelled from the tee.
Five minutes before the break, Guy was the last man to pick-and-drive after some relentless pressure that finally yielded a try and Balbirnie converted.
The outhalf kicked another penalty with the last kick of the half to make it 13-3.
Castleknock threw everything at their opponents in the second half but rarely looked like getting the five-pointer they needed.
Brookes did land two fine penalties to reduce the margin to four but it was only in the closing minutes that they got close to the Andrew’s try line.
They were unable to find the gap they so badly needed though and Andrew's took the honours.
ST ANDREW'S: A Fogarty; J Larmour, G Fearon, M Kirk, G Beere; J Balbirnie, D Joyce; A Porter, A Brady, D Higgins; J Cassidy, A Guy; J Guy, B Ingram, G Jones. Replacements: R Bradley for A Guy (49 mins).
CASTLEKNOCK COLLEGE: C Doddy; S Voden, C O'Shea, K Dixon, S McEntaggart; D McConville, C Lynch; G Brookes, T Hanlon, S O'Heir; E Murphy, J O'Sullivan; D Scanlon, D Byrne, N O'Riordan. Replacements: Z Butt for O'Heir (46 mins).