Instead, they exhausted all the will from 'Rock for tight-head prop Dylan Murphy to earn his place in immortality by landing the crushing final blow from no more than three metres to take them over the top of the champions.
It was no more than Roscrea deserved. Forget the inch-by-inch warfare they engaged in and recall the concentration and commitment to the cause that enabled flanker Matty Keane to put them ahead in the fifth minute.
From then, the script developed as written with captain Hugo Kean pounding over from close range and excellent centre Gavin Mullin carving up an exquisite try for wing James McGowan's conversions to make it 14-5 to the holders at half-time.
However, the sheer brilliance of number eight Dan Trayers drove Roscrea to unimaginable heights.
Scrum-half Keith Kavanagh's steepling up-and-under forced a spill and fly-half Alan Tynan miraculously plucked up the ball, held off a challenge and grounded the ball in the right corner to reduce the lead to four points in the 50th minute.
From there, they went blow-for-blow as Roscrea battled against the elegance of 'Rock's attack with a locked-down, body-sacrificing disregard for what the record books had told them.
They would not be denied. Trayers was the catalyst; Murphy the history maker.
Roscrea: T Carroll; S Kilgallon, R Wharton, T Foley (capt), D Keane; A Tynan, K Kavanagh; L Walsh, E Maher, D Murphy, F Wycherley, A Browne, S Meagher, M Keane, D Trayers.
Replacements: B Diffley for Keane 50 mins; K Cahir for Meagher 56 mins; P McKeon for Browne, J Murphy for Wharton both 68 mins.
Blackrock: S Kilgallen; T O'Brien, G Mullin, K Dixon, J McGowan; C Dean P Patterson; M Reidy, H Kean (capt), R Mouatt, D Mullane, V Mantegazza, R McMahon, J Fairley, C Doris.
Replacements: C Ryan for Mullane 14 mins; J Fennelly for Dean 30 mins; E Burns for Mouatt 55 mins; A Murphy for Fairley 62 mins.