Blackrock's merciless display of attacking rugby at Donnybrook yesterday sent them cruising into the semi-final. Five tries in the first half was more than enough to crush The High School.

When David Nyhan's break set up the opening try for Ryan Walsh after just three minutes, The High School knew exactly what was in store.

Nothing could stop Cian McNaughton's next score on 17 minutes with outhalf Jason Quinn and Nyhan once again involved in the build-up and it wasn't long before more followed. Walsh's solo run brought his second try and even though Quinn limped off injured after 23 minutes, his replacement Morgan Crowe soon added two more.

That left the half-time score at 29-0. The High School rallied briefly but Barry John Leahy added a sixth Blackrock try, converted by Stephen O'Brien, while McNaughton, Walsh and Nyhan continued to run unabated in the three-quarter line. Indeed, their final score on 46 minutes went to McNaughton.

Blackrock eased off the pedal in the final quarter hour as they experimented with a succession of substitutions.

It still proved all so fruitless for The High School, although they picked up a consolation try when Rob Smyth's determined run brought him over the line a minute into added time.

Blackrock College: S O'Brien; C Moore, D Nyhan, R Walsh (capt), C McNaughton; J Quinn, C Willis; A Franciosi, J Coady, D Soden, R Quinn, S Moloney, S McClafferty, K O'Toole, B J Leahy. Replacements: M Crowe for Quinn (23 mins), Holland for O'Toole (36 mins), A Hughes for Holland (42 mins), R Parkinson for Franciosi (47 mins), M Kavanagh for Willis (49 mins) R Tevlin for Coady (55 mins).

The High School: R Smyth (capt); R Thackaberry, A Feldman, B Campbell-Crawford, G Murphy; D Thompson, M Darcy; D Lee, E Mahon, S Goldsmith, P Anglim, L Doyle, D O'Byrne, R Condron, M Kelly. Replacements: R Bose for Lee (half-time), B Hannon for Mahon and E O'Reilly for Doyle (both 43 mins).

Referee: D Keane (Leinster Branch).