All the goals came in the second half with Jamal Ibrahim giving Dundalk the lead on 54 minutes with a low drive that managed to beat Dylan O’Neill in the Cabra Goal.
But the Dublin outfit hit back almost immediately when Ray O’Sullivan found space in the 18-yard box to fire past keeper David Odumosu.
And they could have gone ahead two minutes later when Luke Wade Slater’s header struck the bar.
However it was Dundalk who were the side who scored next. Oran O’Hanlon found the net with a header when he converted from an excellent Ebuka Kwelele cross.
The pair were involved again for the third Dundalk goal when Kwelele’s effort was parried by O’Neill but only into the path of substitute O’Hanlon who made no mistake in wrapping the game up.
Dundalk finished the game with 10 men when Kwelele was shown a second yellow card late on.
Cabra ETB: O’Neill; O’Sullivan, O’Shea, Finnerty, McKenna; Mutawe, Redmond (Okosun 46), Lyons, Mashigo; Wade Slater (C); Aluebhosele (Animashaun 75)
Dundalk ETB: Odumosu (C); Beslic, Dooley, Soraghan, Traynor; Gough (Rielly 80), O’Brien (O’Hanlon 64), Kwima (Caffrey 75); Kwelele, Shield, Ibrahim