Ardscoil Ris advanced to the semi-finals after a hard-fought victory over Presentation Brothers College, Cork.
The Limerick school dominated the first half and took an early lead, with the impressive Conor Fitzgerald striking two penalties.
Just before the break, Ardscoil made their dominance count and crossed for a try through Peader Collins.
Fitzgerald added the extras with a fantastic strike from way out on the touch line which gave his side a 13-0 lead at the break.
PBC, though came flying out of the blocks in the second period and scored two tries in the space of three minutes.
Brian O'Mahony was first to cross the line after his side won a five-yard scrum against the head.
PBC were immediately back deep in the Ardscoil '22'. Fiachra Kelleher forced his way over from a close-range line-out to leave just three points between the sides.
The Ardscoil Ris defence held firm and they grabbed a try against the run of play through captain Jerry McCabe.
Man of the match Fitzgerald fittingly had the final say with another brilliant touchline conversion straight between the posts to give his side a deserved 10-point win.
Ardscoil Ris – D Gavin (J Brennan 56); M Fitzgibbon, P Collins, J O'Donnell, N Randles; C Fitzgerald, J Moore; P Lyons, Ty Chan, J O'Shea (T Richardson 40); C Cannon, R Coffey; I Brown, J Sexton, J McCabe (capt).
PBC Cork – S Lucey; S O'Brien, J Costello, R Murphy (K O'Leary 30), C Duggan (P Fitzgerald 43); B Ryan (P Sylvester 30), B Pope; C Ormonde, M Shinkwin (C O'Flynn 48), S Deane; F Kelleher, E O'Shea; G Smith (capt), C Fitzgerald (L O'Connor 30), B O'Mahony.
REF – D Noonan (MAR).