A brace of Stephen Sherlock points fired them ahead and their early dominance was cemented by a Robert O’Mahony goal on 13 minutes, 1-6 to 0-1 they led.
Carbery Rangers were reliant on John Hayes' dead-ball accuracy so not to lose touch and their first score from play arrived via John O’Rourke in first-half stoppages, 1-8 to 0-6 the interval scoreline.
Carbery Rangers thrice pared the margin back to four, but come not come any closer.
Robert O’Mahony kicked St Finbarrs’ second goal on 45 minutes and their passage to the decider was rubberstamped by a Colm Keane goal late on.
In the other semi-final, Nemo Rangers hammered Duhallow, 5-13 to 0-12, to set up a city derby in the final.
S Sherlock (0-9, 0-6 frees); R O’Mahony (2-1); C Keane (1-0) E Dennehy (0-2); D O’Brien, R Leahy (0-1 each).
J Hayes (0-8, 0-8 frees); K Fitzpatrick (0-2); B Shanahan, K McMahon, S Hayes, J O’Rourke (0-1 each).
D Murphy; S Ryan, A McCarthy, D Quinn; J Burns, G O’Connor, A O’Connor; I Maguire, E Comyns; D O’Brien, M Shields, E Dennehy; S Sherlock, R Leahy, R O’Mahony.
C Keane for Comyns (48); E McGreevey for O’Mahony (55); I O’Callaghan for O’Brien (57); P Kennedy for O’Connor (60); C Scully for Quinn (60); C Barrett for Leahy (61).
A Roche; T O’Rourke, B Shanahan, R Hegarty; J O’Riordan, R Kiely, P Hodnett; K McMahon, J Fitzpatrick; C O’Donovan, S Hayes, A Jennings; M Hodnett, J O’Rourke, J Hayes.
M Kelly for O’Donovan (HT); D Hayes for M Hodnett (45); S Murray for P Hodnett (49); B Hodnett for S Hayes (52)
J Bermingham (Bride Rovers).