Leading by seven points and deep into injury time, this game was petering out with holders Christians heading for a local derby tie against PBC in the quarter finals with a 19-12 advantage, Ardscoil Ris made one final effort to save the game.
They brought play into the CBC Twenty Two and after several drives at the line substitute Nathan Randles barged over in the corner to touch down. Ice cool out half Conor Fitzgerald kicked a magnificent conversion from the touch line to level the scores and with that kick the final whistle sounded.
There was great joy amongst the Limerick players and supporters as they were the winners on the first try rule.
If there was a dramatic finish, there was also an explosive start with each side scoring a try inside the opening five minutes.
It was Ardscoil Ris who opened the scoring when full back Darren Gavin broke through the Christians defence to score and Fitzgerald added the extras.
Straight from the kick off Christians had their opponents on the defensive and from a scrum inside the Twenty Two Darragh McGinn broke and prop Conor Leahy got over the line to score and Michael O'Halloran levelled with the conversion.
Ardscoil should have gone back in front on twelve minutes when a well worked move by the backs saw Gavin join the line but his final pass to James Brennan was knocked on. Five minutes later in a repeat move Brennan caught the ball and made sure to score in the corner for a 12-7 advantage.
Christians hit the front two minutes from half time. A quickly taken penalty saw winger Ben O'Callaghan get the ball and he had the confidence to barge over in the corner and O'Halloran expertly converted for a 14-12 half time lead.
The Sydney Hill College continued to dominate at the start of the second half and were rewarded with another fine try by Alex McHenry on thirty six minutes following aruck inside the Ardscoil Twenty Two..
Christians grew in confidence as the game went on but then came that final salvo by the Limerick side who will now face PBC in the quarter finals while CBC must await the winners of the Rockwell v St. Munchin's tie on Friday.
CBC: Ian Dorney; Ben O'Callaghan, Alex McHenry, Oisin Conway, Alex O'Brien; Michael O'Halloran, Robert McGuire; Gary Maloney, Fergus Hennessy, Conor Leahy; Darragh O'Donovan, Cameron Penney; Eoin Feeney, Eoghan Cahill (Capt), Darragh McGinn. Replacements: Gordon Good, Ciaran McHugh, Robert Hyde, Declan Barry, Richard Cassidy, James Taylor, Killian O'Sullivan, Tom McKenzie
Ard Scoil Ris: Darren Gavin; Michael Fitzgibbon, Peadar Collins, Jack O'Donnell, James Brennan; Conor Fitzgerald, Jamie Moore; Pierce Lyons, Ty Chan, Jack O Shea; Conor Canon, Ronan Coffey; Oisin Bernard, Jack Sexton, Jerry McCabe (Capt). Replacements: Luke Moylan, Tyler Richardson, Robert Leonard, Ian Brown, Ben Devlin, Eoin Ryan, Nathan Randles, Marcus McManemy.
P.B.C. 5, Crescent College Comprehensive 16.
A deserved victory for the Limerick side even thought it was eight points in injury time that finally made sure of a home quarter final tie for Crescent against Glenstal Abbey.
Crescent opened the scoring with a penalty from Cian Clifford after ten minutes and they dominated proceedings especially at line out.
Once Pres settled they worked the ball into the Crescent 22 and pounded the line and were awarded with a try by Luke O'Connor after twenty one minutes.
A break by Crescent skipper Calvin Nash sent full back Glen Dickinson in for a Crescent try two minutes before the break to lead 8-5 at half time.
The second half saw Crescent lose a player to the sin bin inside the opening minute of the second half but Pres' failed to capitalise.
A break by Nash nearly extended the Limerick side's advantage when he chiped the ball ahead and won the race but knocked on just short of the line.
Pres' rallied in the closing stages but a twenty eight meter penalty by Barry Ryan fell just short.
Back came Crescent and Clifford kicked a penalty in the fourth minute of injury time and from the restart Dickinson passed to Billy O'Hora inside his own half and the Crescent center burst through the Pres' defence to score in the corner.
P.B.C: Patrick Fitzgerald; Shane O'Brien, Sean Lucey, Ross Murphy, Conor Duggan; Barry Ryan, Billy Pope; Conor Ormond, Michael Shinkwin, Sam Deane; Fiachra Kelleher, Luke O'Connor; Graham Smith (capt), Eoin O'Shea, Brian O'Mahony. Replacements: Niall O'Brien, Kyle Harte, Ryan Butt, Daire McDonogh, Cian Fitzgerald, Conor O'Dwyer, Kevin O'Leary, Jimmy Costello.
Crescent College Comprehensive: Glen Dickinson; Conor McSweeney, Billy O'Hora, Calvin Nash (capt), Jordan Young O'Connor; Cian Clifford, Jack Lyons; Anson Thai, Jason Barry, Sean Scanlon Garry; Brian Considine, John Blake; Conor Slattery, Peter Hickey, Niall Mulcahy.Replacements: Brian Ryan, Sean Downes, Ed Barry, Luke O'Connell, Joe Barry, Michael Mullins, Andrew Reeves, Bailey Faloon.