Speed of foot and mind was supposed to be the difference between these two. And so it proved.
The capacity for Terenure to absorb any amount of physical punishment and strike like an arrow from counter-attacks was the only reason they moved beyond a Roscrea outfit fully committed to making it to the senior and junior finals for the first time.
The pre-competition favourites were able to take down Roscrea's huge, hulking forwards through their commitment to the chop tackle as No 8 Conor Shenton led the way.
Centre Adam La Grue and full-back Sam Dardis, younger sibling to Ireland U-20 star Billy, were able to fix defenders and slip scrum-half Matthew O'Shea in for a fifth-minute try.
Just when it seemed the Roscrea forwards were beginning to take control, the ball broke free for La Grue to take it three-quarters the length of the field and apply the conversion for a 12-0 lead in the 28th minute.
It was a long way back from there and Roscrea had to handle the loss of their captain Adi Donovan and stand-out forward Michael Milne at half-time.
They didn't seem too bothered by this and hit home with tries by flanker James Corcoran and scrum-half Liam Crowley in the 35th and 47th minutes.
A lightning raid, sparked by Dardis, resulted in a penalty angled over by La Grue to make it 15-10 in the 52nd minute.
'Nure had enough left in the tank to see it out and set up the prospect of a final against Blackrock on Sunday week.
Terenure - S Dardis; L Murnaghan, A La Grue, J Walsh, J Nolan; D Henry-Hayes (C Creed 56), M O'Shea; B Vaughan, B Bruce, L Vaughan, C Somerville (capt), R McGrath, P Heneghan (J Cooke 46), L Grady, C Shenton.
Roscrea - R O'Halloran; M O'Leary (B Murphy 50), J Culliton (T Martin 42), A Donovan (capt, B Foley h-t), R Deacy; E Browne, L Crowley; R Lomas, J Cahir, K Fitzgerald, D Maher (D Loughnane 22 temp; S Clancy 35), D Power, J Corcoran, M Milne (D Loughnane h-t), L Rigney.
Ref - G Glennon (Leinster Branch)