An unusual goal in the 31st minute at Oriel Park on Saturday night put Dundalk on the road to victory.
Half an hour into the game Dundalk put together one of their best passing movements, which ended with Tommy Byrne floating the ball into Limerick penalty area.
David Hoey, with his back to goal, somehow managed to flick the ball over his head and past the astonished goalkeeper in the Limerick goal.
Limerick tried hard to recover, but Dundalk more or less put the game out of their reach with another strike against the run of play by John Flanagan in the 57th minute.
Then, with Dundalk dominating the game in the closing stages, Martin Reilly added a third in the 83rd minute.
Dundalk: Connolly, Hill, Crawley, Broughan, Callaghan (Dunne 64 mins), Byrne Whyte 82 mins), Flanagan, A Reilly (Martin 82 mins), M Reilly, Hoey, Mullen.
Limerick: Fitzpatrick, Hand, Lynch (Finnan 77 mins), O'Halloran, D Whyte, J Whyte, Dunphy (Keating 68 mins), Ryan, Weldrick O'Sullivan 76 mins), McCarthy, Harmon.
Referee: P Whelan (Dublin).