Castleknock secured the Bank of Ireland Leinster Schools Junior League title for the second time in three seasons at Donnybrook on Wednesday.
The first crack came quickly when their centre Sean Casey hit a fine line and flanker Alec Bernie was on his shoulder to take a lovely angle onto the ball which outfoxed the cover for full-back Oran Farrell to convert in the fourth minute.
They were not able to control the restart and a bind slipped at the scrum put Roscrea in place to strike back, their out-half Dylan Keane settling for a grubber when all options had been exhausted.
It wasn’t long before ‘Knock made them pay for lack of a cutting edge, full-back Oran Farrell sweeping the ball left from a clearance kick.
Wing Shane Duggan carried well and captain Fionn Gibbons was in the right place at the right time to glide over for the second try in the 10th minute.
A smart blindside move ran aground against Roscrea’s fringe defence, led by Sean Frawley and Jarlath Connolly.
It was one-way traffic, the Dublin school motoring forward for wing Blaine Keogh to test out centre Harry Kenny and they find the line again from Casey’s offload off the floor to the waiting Gibbons, Farrell’s conversion making it 19-0 in the 16th minute.
Roscrea prop Adam Kennedy and hooker Ryan Moran had to be vigilant to prevent scrum-half Conor Duggan causing further damage down the right.
That was a temporary let-off as wing Shane Duggan popped up in the middle to break the cover for a superb individual try, converted by Farrell in the 20th minute.
The Offaly school looked far happier when they got their maul going from a lineout take by number eight Frawley and got their runners moving in close.
They stayed at it, despite the front-foot tackling of Gibbons and Casey, through sound basics at the pick-and-go for prop Kennedy to twist to the whitewash in the 27th minute.
Then, Roscrea produced a scintillating back move, orchestrated by captain Keane, for full-back Sam Murphy to fire through the middle only for wing Blaine Barry to be caught by Gibbons.
It was a reminder of how Roscrea rebounded from a 24-3 deficit in the semi-final just as the half came to a close.
Cistercian came out firing, as they had to do, Keane taking any gap on offer and centre Kenny showing nimble footwork.
Their full-back Murphy blazed onto a flat ball from Keane and the latter added a strong fend on his next carry to get them close and prop Kennedy bulled over from a metre for Keane to smack the touchline conversion for 26-12 in the 40th minute.
Keane’s kicking game was a weapon and the out-half pinned Castleknock back until a ruck penalty enabled him to reduce the gap to 11 points.
It was getting to that point in a game where the next score would be significant. Some tactical kicking from Keane ended in a lineout inside the 22.
There were cracks being forced and desperate tackles had to be made, Gibbons eventually executing a vital turnover.
It was Farrell’s decision to kick for distance that finally lifted the siege, forcing Roscrea to go from deep where they were held up over their own line as time ran out.
At Donnybrook – Castleknock College 26 (F Gibbons 2 tries; S Duggan, A Bernie try each; O Farrell 3 cons); Cistercian College, Roscrea 15 (A Kennedy 2 tries; D Keane pen, con)
Castleknock: Oran Farrell; Blaine Keogh, Fionn Gibbons (capt), Sean Casey, Shane Duggan; Alexander Watson, Conor Duggan; John Ozoani, Greg Spillane, Michael Levesley, Donnchadh Lahert, Senan Forker, Alec Bernie, Gavin Murphy-O’Kane, Luke Callinan.
Replacements: James Duffy for Forker 28 mins.
Roscrea: Sam Murphy; Blaine Barry, Cillian Lawlor, Harry Kenny, Jack Ormond; Dylan Keane (capt), Eoghan Matthews; Patrick O’Connor, Ryan Moran, Adam Kennedy, James Dunne, Jim Byrne, Jarlath Connolly, Willie Conroy, Sean Frawley.
Replacements: Canice Crosby for Barry 49 mins; Ben Bislin for Ozoani 41 mins.
Referee: Jason le Lievre, Leinster Branch.