BLACKROCK COLLEGE 34 CLONTARF 17, Stradbrook
Scorers: Blackrock College: Tries: Fionn Carr 2, David Rowan; Cons: Fionn Carr 2; Pens: Fionn Carr 5
Clontarf: Tries: Paul O'Donohoe 2, Max Rantz-McDonald; Con: Ian Keatley
Fresh from playing and scoring for Leinster 'A' on Friday, Fionn Carr took centre stage in this cup semi-final by scoring 29 points - two tries, two conversions and five penalties.
Incredibly, Clontarf were 31-0 behind at half-time with full-back Carr (2) and winger David Rowan both touching down for 'Rock.
Second half tries from scrum half Paul O'Donohoe (2) and replacement Max Rantz-McDonald were only consolation scores for the visitors, who lie fourth in the Division One table.
'Rock, who are currently seventh in the top flight standings, came into this game having beaten Instonians, Cork Constitution and UCD in the previous rounds of the cup.
This was also Clontarf's first AIB Cup semi-final appearance and they were certainly the match favourites, given their run of eight wins in their last nine league and cup fixtures.
But 'Rock, aided by a slight wind, blew Andy Wood's side out of the water with a memorable first half display.
Before kick-off, Carr had accumulated 131 points in AIB competitions this season and the full-back's early haul of three penalty goals set 'Rock on their way.
The 22-year-old, facing a few of his Leinster Academy colleagues in the 'Tarf team, raised the touch judges' flags after 3, 6 and 12 minutes.
Carr then broke free up the middle, combining with out-half Kyle Tonetti, to scorch over for his and the hosts' opening try which went unconverted.
Continuing his one-man show, the former Newbridge College pupil planted his fourth penalty through the posts for 17-0 lead.
With Tonetti and David Madigan managing to outshine former Ireland Under-20 duo O'Donohoe and Ian Keatley at half-back, 'Rock pressed on.
'Tarf's beefy pack were kept out of the game with 'Rock's front eight aided by the presence of former Leinster pair Shane Byrne and Des Dillon.
Carr's second try arrived in the 31st-minute and it came at the end of a sweeping back-line move as he popped up on the wing before rounding Clontarf full-back Peter O'Brien to score.
The conversion was good and a 'Rock side that also included Leinster flyer Gary Brown managed to put themselves more than four converted tries ahead at the break.
For their third try, the rampaging Carr broke from inside his half and was stopped just short of the line before three quick passes sent Rowan over in the corner.
'Rock did lose their momentum in the second half. They had two players sin-binned - flanker Jaydon Hill saw yellow and hooker Byrne did likewise for tackling a player without the ball.
'Tarf mounted a comeback and had to wait just four minutes for their first try of the second period. O'Donohoe broke off the back of a close range scrum and had the gas to make the line.
The try went unconverted and a Carr penalty, five minutes later, restored 'Rock's lead to 34-5.
O'Donohoe sniped over for another unconverted try in the 67th-minute. 'Tarf kicked well for position in the closing quarter, trying to force the home side into mistakes.
But despite a fine seven-pointer from recent AIB Club international Rantz-McDonald, with the move beginning close to the 'Tarf whitewash and full of some excellent inter-passing, there was no denying 'Rock their place in the final.
They will face either Galwegians or Shannon in the April 12 cup decider - their Crowley Park semi-final was postponed on Saturday due to bad weather.