Victory at Strangmore Park last night saw Cork City book their place in the last four of the Setanta Sports Cup while Dungannon Swifts almost certainly lost their chance of making the play-offs.
The breakthrough goal came seven minutes into the second half and Denis Behan's effort was a worthy winner.
Cork looked threatening in the early stages but Swifts grew in confidence as the first half wore on.
They looked particularly dangerous from set-pieces, Scullion sending a back-header over the bar from Rodney McAree's delivery, before the best move of the half almost brought a Dungannon lead.
Instead it produced an excellent single-handed save from Michael Devine.
McAree played a neat one-two with Mickey Ward before his terrific left-foot shot from 22 yards was denied only by the goalkeeper's fingertips.
McAree's menace was in evidence again in added time in the first half, when he met a fine short pass from Dave Bulow and smashed a curling drive that cruelly crashed off the upright, goalkeeper Devine left to admire the terrific effort from the Swifts talisman.
The Cork men finally ended the deadlock with a goal of sheer quality.
A move down the right side ended with a superb low pass by O'Flynn across a poorly-defended goalmouth.
Behan, lurking at the back post, reacted quickly to slam the ball into the gaping net.
Dungannon responded and after 63 minutes Adamson got on the end of a Thomas Wray pass. An aerial strike from the forward was played perfectly over the badly-placed goalkeeper but came back off the crossbar.
Cork soaked up the pressure and caused their opponents some problems. George O'Callaghan had a shot deflected over after 67 minutes before he forced a low stop from Wells with another decent effort.
Dungannon were almost caught out by poor judgement when O'Flynn raced at the home defence.
Wells came off his line and missed his clearance but McMinn was on hand to save his goalkeeper and clear with a desperate lunge.
DUNGANNON SWIFTS: Wells, Wray, Gallagher, McCrystal, McMinn, McCabe, McAree (Hamilton 83), Scullion, Ward, Adamson (McAllister 89), Bulow (Everaldo 74).
CORK CITY: Devine, Murphy, Bennett, Murray, O'Brien, Fenn (Lordan 90), O'Flynn, O'Callaghan, Woods, Behan, Horgan.
Referee: R Penney (Carrickfergus)
