Substitute Peter Withnell proved the difference between Finn Harps and Dundalk on Saturday night when he came off the bench to score a fine individual goal which gave the visitors all three points.
Having lost only to St Patrick's Athletic at home this season, Harps might well have expected at least a share of the spoils, but their worst home performance of the season insured that would never be the case.
However, they did have chances in the first half when Gareth Callaghan and John Gerard McGettigan forced saves from Steve Williams, but Ian Ferguson and Brian Byrne could also have scored for Dundalk in what was a dull first half.
Two minutes into the second half, Shane Reddish cleared Davy Dowling's header off the line; but the home side rarely threatened after that.
In contrast, substitute Peter Withnell was a constant threat when he came on as a substitute and while he fluffed his first opportunity in the 62nd minute, he made sure of his second in the 75th minute, knocking the ball into the bottom corner to give Dundalk the lead.
McGettigan came closest to replying for Harps, but his two long-range efforts were dealt with comfortably by Williams and Dundalk held on to the points.
Finn Harps: Byrne, McGettigan, Minnock, O'Kane, Dowling, O'Brien, McGrenaghan, Johnston, Speak, Callaghan, Gauld. Subs: Cullen for O'Brien, 68 mins; Bradly for Callaghan, 80 mins.
Dundalk: Williams, Reddish, Crowley, Doohan, Brady, Melvin, Hoey, Byrne, McNulty, McCoy, Ferguson. Sub: Withnell for McCoy, 54 mins.
Referee: J Stacey (Athlone).