Dundalk manager Stephen Kenny will view last night's second-round defeat to Shamrock Rovers as a game that slipped away at the crucial stage.
Back at Tallaght Stadium, where he was once the man leading the home team, Kenny saw his young Lilywhites side end up without a reward for a spirited second-half display.
Ultimately, Ciaran Kilduff's strike on 56 minutes proved to be the difference, but Rovers, as per usual this season, made life extremely difficult for themselves and were hanging on.
It certainly didn't start that way as Trevor Croly's men looked sharp in the opening exchanges as Thomas Stewart forced Dundalk 'keeper Peter Cherrie into a fine save and Shane Robinson hit the post.
Robinson again went close with a header, but Rovers struggled to shift up the necessary gear despite dominating possession and pushing Dundalk back inside their own half.
The game didn't really spark to life until Kilduff controlled a misplaced pass from Dane Massey and smashed in a thunderbolt from distance to put the hosts a goal up.
Dundalk immediately stirred into action with Richie Towell volleying wide before substitute John Dillon and Keith Ward went close. But Rovers did enough to hang on.
SHAMROCK ROVERS – Brush; McCormack, Oman, Elebert, Kehoe (McGuinness 70); Rice, Chambers; McCabe (O'Connor 55), Robinson (Finn 90+4), Stewart; Kilduff.
DUNDALK – Cherrie; Towell, Sullivan, Massey, Osborne; Mountney, McDonnell (Boyle 65); Meenan (Mulvenna 74), Ward, Byrne (Dillon 79); Faherty.
Ref – P Tuite (Dublin).