Bohemians 1 Derry City 2: Another familiar, sinking feeling for the hosts who, having rediscovered a smidgen a self-belief with two victories in the last week, saw a share of the night's prize dissolve.
A fortnight ago manager Gareth Farrelly said game nights at Dalymount resembled Groundhog Day, and he will feel deeply agitated having relived the scenario again so soon.
Still, though, he can have little complaint as his side's lack of discipline early in the second half ultimately swayed the contest.
Bohemians' application during the opening exchanges was admirable and much improved on home performances to date.
Farrelly and Lillestrom-target John Paul Kelly excelled, both propelling the hosts forward with slaloming runs and clever through balls which flummoxed the visiting defence.
But despite that endeavour Bohemians suffered an all too familiar set-back when, having grafted hard, they went behind on 21 minutes.
While the home defence was busy arranging its wall, Barry Molloy found space on the edge of the area and finished low past Stephen O'Brien once Kevin Deery nonchalantly rolled the free his direction.
Determined to atone for the slack manner in which they conceded, Bohemians pressed on in search of an equaliser.
Farrelly, as dominant tracking back as he was surging forward, went close with a shot from distance, forcing David Forde to tip around his post.
However, it was his application in and around the box which proved more rewarding. Time and again he teased in crosses which, but for desperate defending, could have been punished by any number of Bohemians' players queuing up.
That persistence paid off. After Sean Hargan grounded Kelly five minutes before the interval, Farrelly drilled the resulting free low and hard through a maze of legs. Forde was well positioned to collect but was unsighted by striker Vinny Arkins and the manager's innocuous ball trickled over the line.
Derry, though, restored their lead seven minutes into the second half. Amid of sea of bodies, referee Alan Kelly - who later dismissed Thomas Heary for dissent - adjudged Barry Ferguson to have fouled in a crowded box as a corner floated in.
The decision seemed particularly harsh but striker Mark Farren dispatched the ensuing penalty emphatically.
Bohemians finished strongly but were fortunate not to have conceded a third when substitute Kevin McHugh shaved the post with an angled strike late on.
Bohemians: O'Brien; Rice (Devlin 77), Ferguson, McGuinness, Byrne; Harkin (Hunt 57), Heary, Farrelly, Kelly; Arkins, Ward. Booked: Ferguson (52), Farrelly (52). Sent off: Heary (55)
Derry City: Forde; McCallion, Kelly, Hutton, Hargan; Deery, Higgins, Molloy, Brennan; Beckett (O'Flynn 86), Farren (McHugh 68).
Referee: A Kelly (Cork)
