RBAI 22 RS Armagh 29
It was quite a game and, somehow, Royal School Armagh turned this contest on its head to book a place back at Kingspan Stadium on St Patrick's Day.
Trailing 22-5 early in the second half, Armagh's challenge looked over as Royal Belfast Academical Institution had scored three tries and were seemingly cruising to a surprise victory.
Yet Armagh were the victors after racking up an astonishing 24 unanswered points in what remained of this pulsating semi-final.
True, they found a way back into the contest by scoring two converted tries, 14 pivotal points, during flanker Jonny Eagleson's sin-binning, but the real turning point came when the Belfast school were back to full strength as Armagh flanker Josh King then piled through for their fourth try to put them 24-22 up.
Inst, who had played with such authority for most of the game, could scarcely absorb what was happening as Armagh, with confidence coursing through them, then finished the stronger to secure their 14th final.
Armagh coach Willie Faloon was also taken aback at snatching victory from what had seemed inevitable defeat.
"We were 100% dead and buried," he said of going 22-5 behind in the 41st minute after having been 8-5 down when the sides changed ends.
"I had definitely given up hope at that stage but thankfully the lads hadn't.
"We got a little turn of fortune as they sustained a yellow card, and maybe the tide turned a little bit as we got scores and then started putting pressure on them.
"But for us to come back is all credit to the guys."
Yes, it was quite a match. Eight tries scored in all, with Armagh banking five of them, lock Nicholas Bothwell, scrum-half Charlie Worth, replacement back James Allen, King and full-back Ethan McAtarsney all dotting down for the eventual winners.
They also possessed arguably the game's outstanding forward in hooker and captain Sam Rainey, whose appetite for work helped sustain them throughout.
Inst's Ronan Boyle, who ended the afternoon scoring 12 points, started things off for the Belfast school with a well-struck penalty after just three minutes.
While Inst were prepared to give the ball width, and play with ambition, Armagh seemed intent on the direct route and even turned down a kickable penalty to opt for a scrum and more close-in drives which Inst ably resisted.
It looked as if Armagh's moment was over, but then a sliced exit kick from Inst saw McAtarsney counter and, after a scramble near the line, Bothwell surged over.
Romain Morrrow missed the conversion but Armagh had the lead on 24 minutes.
It didn't last, though. Off a scrum on the left, Inst moved the ball through the hands and after Oscar Lowe's initial line-break, Jude Postlethwaite then put Boyle in space and the full-back made the line.
His attempted conversion failed to bisect the posts but, crucially, Inst were now back in front having been behind for only four minutes, and it was they who led 8-5 at the interval.
Inst then had the perfect start to the new half when winger Oliver Metcalfe did well to smash through several tackles to score at the corner, and Boyle even managed a magnificent touchline conversion to put Inst 15-5 ahead after just two minutes of the second period.
That became 22-5 shortly afterwards when Postlethwaite's break and pass allowed Paddy Eames to make the line near the posts, Boyle adding a more straightforward two points.
Inst then lost flanker Eagleson to the bin in the 45th minute and Armagh quickly pounced, with the lively Worth wriggling over. Morrow's conversion cut Inst's lead to 10 points.
Further progress came on 50 minutes when Sam Cunningham broke out and the Armagh winger threw a lovely inside pass to his left for Allen to score.
Morrow converted and now Armagh were just three points behind. Even though Inst were now back to 15, the Royal School struck again.
After a penalty was put into the corner, Armagh mauled forward and King put the ball down and, though Morrow's conversion hit the post, Armagh now led 24-22.
Inst, though, still had a way back as Morrow then missed a 63rd-minute penalty, but then came the killer blow as Armagh opted to spread the ball wide on the left.
Allen made ground before passing to McAtarsney, who dived over in the left corner.
It hardly mattered that Morrow was short with the conversion as full-time was blown, allowing the Royal School to celebrate an incredible comeback.
What a game, though Inst will find no consolation from that.
RBAI: R Boyle, O Metcalfe, J Postlethwaite, O Lowe, J Dickson, H Ellerby, J Patterson; A Byrne, R Adair (capt), S McAuley, A Weir, S McLarnon, P Eames, J Eagleson, B Cooke.
Replacements: J Cuthbert, L Greene, S Collins, T Simms, A Cooke, B Beattie, R Stewart, J Leathem.
Royal School Armagh: E McAtarsney, S Cunningham, P Taylor, R Taylor, C Whiteside, R Morrow, C Worth; N Carville, S Rainey (capt), J Roberts, J Denley, N Bothwell, J Agnew, J King, R Finlay.
Replacements: J Cunningham, D Poyntz, J McBride, K George, A McSorley, J Hazelton, J Allen, S Harrison.
Referee: J Wilson