Lady Luck was not on Dolphin's side as they constantly battered the Constitution line in the final 20 minutes of the game, after they fell 11-6 behind at the end of the third quarter.
This was Con’s first win over their local rivals and they became the winners of the inaugural Keary’s Cup.
There was little between the sides in the opening half as both packs began to test each other and to their credit both sides tried to play an expansive game with Con wingers Darren Sweetnam and Rob Jermyn always looking dangerous with ball in hand.
Tomas Quinlan opened the scoring with a penalty for Con after ten minutes following a high tackle.
The Dolphin pack was slow to get going but once they began to get the better of the exchanges Rory Scannell had the visitors level after 20 minutes.
Four minutes before half time a crunching tackle by Con's Ger Sweeney on Ryan Murphy just outside the Con 22 resulted in Murphy being stretchered off the field with an arm injury.
Dolphin lost the momentum and Quinlan saw a penalty effort just go wide four minutes into injury time, but two minutes later he was successful with an easier attempt to give Con a 6-3 half timelead.
Dolphin started the second half on top but Scannell missed a simple penalty effort to level and minutes later he had the sides level with a difficult effort.
Quinlan was off target with a drop goal effort, but Con had Dolphin pinned back in their own 22 and from a Con lineout the pack mauled the ball over the line and Max Abbott touched down for an 11-6 lead.
Dolphin's response was quick as their pack brought the play into the Con 22 and following several drives at the Con line, some brave tackling held them out.
Dolphin winger Shane McAuliffe was stopped by Darren Sweetnam and the former Dolphin player was yellow carded for his efforts.
Dolphin were awarded several penalties and opted for touch. Rob O'Herlihy gained possession but the pack made a futile drive for the line.
James Murphy cleared the danger and two injury-time penalties by Quinlan denied Dolphin a losing bonus point.
CORK CONSTITUTION: D Lyons, D Sweetnam, N Keyes, N Kenneally, R Jermyn, T Quinlan, G Hurley, G Duffy, A O'Driscoll, G Sweeney, C O'Flaherty, D O'Brien, G Lawlor, J Murphy, J Ryan.
Replacements: M Abbott, C Corkery, F McSwiney, L Cahill, L Duffy
DOLPHIN: E Mills, E O'Shaughnessy, M Chandler, D Horgan, S McAuliffe, R Scannell, K O'Keeffe, P McCabe, K O'Halloran, J Rochford, B Quill, D O'Mahony, R O'Herlihy, J Quill, R Murphy.
Replacements: D Byrne, J Leahy, J Fitzgerald, C McGovern, B Keeshan.
Referee: K Barry (IRFU).