Galvin brace inspires Gonzaga
Gonzaga 14 Castleknock 10
A brace of first-half tries from Sean Galvin proved decisive for Gonzaga at Donnybrook.
A try on the hour mark by Castleknock's Darragh McNally set up a tense finale, but the Ranelagh school held firm to set up a last-eight clash with Cistercian College Roscrea.
Eight-time winners Castleknock had opened the scoring with a ninth-minute Cian Egenton penalty, but winger Galvin soon crossed after an excellent James Kenny off-load.
Gonzaga stretched their advantage when Galvin was on hand to finish off a fine move, and Michael O'Kennedy's second conversion made it 14-3 at the break.
With Ian O'Grady in the sin-bin, Castleknock made their numerical advantage count as flanker McNally touched down under the posts. Donncha Ryan's conversion cut the gap to four points, but Gonzaga held out.
Gonzaga College - D Lynch; S Galvin, H Twomey, B O'Donnell, E Allen; M O'Kennedy, J Kenny; M Gleeson, C Gleeson, S Clear; E Buggy, C Fassbender; I O'Grady, M Keegan, R Kidney.
Castleknock College - C Lacey, R O'Meara, J Branagan, J McGaley, L McMenamin; C Egenton (D Ryan 46), C Neville (J Connolly 46); E Reilly, M Corcoran, J Keleghan; C O'Brien, J Horgan; J Gillen (A Corcoran 41), D McNally, C Clancy.
Ref - B Montayne (LRR).