Four minutes of madness led to Dundalk's elimination from the FAI Cup at the Brandywell yesterday and their young central defender Padraig Gallogley will have nightmares about this game.
Nineteen-year-old Gallogley gave Derry City the vital breakthrough in the 24th minute when he drove the ball into his own net. And, unfortunately for the teenager, he was credited with another howler four minutes later, allowing Derry's striker Liam Coyle to end this game as a contest.
But Dundalk's preparations could not have gone worse. In the pre-match warm-up, robust central midfielder Lee Thew, who was returning to the action following injury, went over on his ankle and had to be withdrawn.
Dundalk never seriously threatened the Derry goal after conceding the two goals in the first half. The home side did a professional job in the second period, retaining possession and defending in depth when necessary.
Gallogley's own goal was fashioned by a break on the right by Michael McHugh and when his powerful low centre entered the danger area, the Dundalk defender hammered the ball high into his own net giving the startled Steve Williams no chance.
In the 28th minute, Gallogley's weak and misdirected headed clearance dropped at McHugh's feet and with Coyle breaking to his left, the Donegal man laid off the perfect pass to sent his fellow striker on his way.
Coyle finished with aplomb, skilfully guiding the ball wide of the advancing Williams to find the corner of the net.
Dundalk huffed and puffed and while they did enjoy lengthy periods of possession after the break, they failed to penetrate a resolute Derry defence in which skipper Peter Hutton was outstanding.
"Despite defeat, I felt we learned so much from the game," said Dundalk boss Jim McLaughlin afterwards. "We didn't play in the first half. However, after a chat at half-time we got it right and our youngsters began to express themselves.
"As I've said, we learned a lot and that will stand us in good stead for the vital league games we face in the weeks ahead.
"I've no problem with the result. Derry were the better side and deserved to win. While I'm disappointed at going out of the cup, Cup, our priority at the moment is Premier Division survival," he concluded.
Derry City: Platt; D Kelly, Curran, Hutton, M Kelly; McCallion, Hegarty, Doherty, Hargan; Coyle, McHugh. Subs: McCann for Hargan (53 mins), McCaul for Coyle (63 mins), Gallagher for McCallion (85 mins).
Dundalk: Williams; Reddish, Gallogley, Melvin, Crawley; Dunne, Campbell, McNulty, Sharkey; Martin, Ward. Subs: Brady for Sharkey (52mins), Harte for Dunne (59 mins), Byrne for Martin (78 mins).
Referee: H Byrne (Dublin).