Derry City fell just short at the Brandywell as Stephen Kenny led Dundalk to a second FAI Cup final in two years.
The holders had to do it the hard way last night, however, as they came from behind - after the teams drew 2-2 in Sunday's first clash - to clinch the semi-final replay, recovering from conceding an early Ronan Curtis goal to win thanks to efforts from Ciaran Kilduff and Ronan Finn.
It was heartbreaking for Kenny Shiels and his players, who came so close to making the Aviva final on November 6, but in the end the difference was the extra bit of quality that the visitors produced out of nothing, as shown when Finn headed in the game's winning goal.
The Candystripes got off to the perfect start as they opened the scoring with just three minutes on the clock to send a packed Brandywell into raptures.
Harry Monaghan won the ball off Paddy Barrett and flicked it into the path of Barry McNamee.
The midfielder turned and passed in one movement and played a superb ball into the path of Curtis, who flicked past Gabriel Sava and into the net to produce a Brandywell roar not heard since the semi-final replay win over Shamrock Rovers in 2014.
Both sides traded corners, with Brian Gartland heading just wide while Aaron McEneff shot over after a clever pull back from McNamee. It was only midway through the first half, but the game promised more goals.
And that proved to be the case as Dundalk drew level on 37 minutes. The goal came when Robbie Benson broke into the area and sharply turned beyond Niclas Vemmelund, who stuck out a foot to stop the Dundalk man shooting and brought him to the ground.
Referee David McKeon hesitated, but fifth official Paul Tuite, behind the goal, confirmed the foul and Dundalk had a penalty. Kilduff (right) placed the ball on the spot and, although Gerard Doherty guessed the right way, the penalty was sent into the corner and Dundalk were level.
Curtis very nearly repeated the dose in the early stages of the second half as he broke into the Dundalk penalty area and, after holding off two challenges, he brought a good save at the near post from Sava, who was grateful that the rebound fell to a black shirt and the ball was hacked away to safety.
Derry were matching Dundalk every step of the way in the second half and McEneff brought a fine save from Sava with a 20-yard drive which had the goalkeeper scrambling to his right. But just 60 seconds later it was 2-1 to Dundalk and the Brandywell was silenced.
Darren Meenan was given time to cross from the right and his brilliant ball into the heart of the penalty area, where three Dundalk players were waiting, was met by Finn, who guided a header beyond the dive of Doherty and into the corner to give the cup holders the lead.
City huffed and puffed after that, but Dundalk, despite an exhausting schedule, held them at arm's length with a wayward shot from Conor McCormack the best that the hosts had to offer.
The Candystripes now turn their attention to securing a place in European competition next season, with a top-four finish sufficient should they hold on in the final weeks of the season.
DERRY: G. Doherty, Vemmelund, Jarvis, McEneff, McCormack, McNamee, Monaghan (Schubert 90), Patterson, B Doherty (Boyle 83), McDermott, Curtis.
Dundalk: Sava, Gannon, Gartland, Shields, Mountney, Finn, Grimes, Barrett, Kilduff (McMillan 64), Benson (Horgan 45), Meenan Boyle 75).
Referee: Dave McKeon (Dublin)
Man of the match: Ronan Finn (Dundalk)
Match rating: 6/10