The Kerry champions will face John Mitchels from Liverpool in the decider in a fortnight.
Yesterday’s semi-final replay was a tough and physical encounter from the outset, and ultimately Rock’s ill-discipline cost them dearly.
It was 0-7 to 0-4 in favour of Brosna at half-time but Rock took control in the second half despite Ryan Crilly seeing red and their captain Aidan Girvan getting black.
They tied the game with time running out but Mike Finnegan hit 1-1 in the final five minutes for the Kerry champions to book their place in Croke Park
Brosna raced from the blocks and star forward Adam Barry got their first point inside a minute, Aidan Girvan equalised moments later.
They went score for score until a 10-minute spell before half-time when Brosna punished Rock’s ill-discipline in defence.
Tom McGoldrick kicked five frees before Conor McCreesh’s effort left the Tyrone champions trailing by three (0-7 to 0-4) at half-time.
Brosna wouldn’t score again until the 56th minute but Rock had troubles of their own.
Crilly got red for a high tackle on McGoldrick minutes after McCreesh had brought his side within two points, and after Martin McCreesh put the minimum between the sides, the Tyrone men lost Aidan Girvan to a black card.
Ciarán Gourley’s point drew the sides level for a fifth time but the extra-man advantage was going to tell in the closing stages.
Brosna launched one decisive attack with four minutes remaining and following a goalmouth melee, the ball found its way to Mike Finnegan, who rifled home to the bottom corner.
And his point moments later sealed a memorable win for the Kerry representatives.
Scorers for Brosna: T McGoldrick 0-5 (5f); M Finnegan 1-1; A Barry 0-2.
Scorers for Rock St Patrick’s: C McCreesh 0-4 (2f); A Girvan, M McCreesh, C Gourley 0-1 each.
BROSNA: E Prendeville; S Fitzmaurice, M Murphy, A Cahill; T Fitzgerald, E Kiely, F McAuliffe; D Curtin, S Curtin; Don McAuliffe, T McGoldrick, P Curtin; T Finnegan, M Finnegan, A Barry.
Subs: P O’Keefe for P Curtin (37), J O’Donnell for D McAuliffe (53), S McAuliffe for T Finnegan (60)
ROCK ST PATRICK’S: N Mullan; M McAleer, P Girvan, R Crilly; T Bloomer, A Girvan, P Ward; M McCreesh, C Gourley; E McWilliams, A McGarrity, C McWilliams; E Ward, C McCreesh, J McCreesh.
Subs: N McWilliams for T Bloomer (8), K Kolbohm for J McCreesh (37), D Carroll for A Girvan (Black, 47)
Referee: Jerome Henry (Mayo).