Patrick Hoban scored a goal in each half to lay the foundations for a comfortable Dundalk victory at Finn Harps.
Michael Duffy and Greg Sloggett added further goals to help the defending champions move level on points with Shamrock Rovers at the top of the Premier Division table.
A Hoban shot from the edge of the penalty area took a nick and looped over Mark Anthony McGinley to give the league champions the opener with only 140 seconds on the clock.
Eight minutes before half-time it was 2-0. Michael Duffy steered home a rebound at the Town End after Daniel Kelly had inexplicably shot off the underside of the crossbar with the goal yawning at his mercy.
Duffy, who set up the chance in the first place with a squared ball, got the rewards for his selflessness.
In between times, Harps were robust and the closest they came to a leveler was on 13 minutes when goalkeeper Gary Rogers did exceptionally well to turn away a curving effort from Mark Russell, who came inside on his right foot to have an effort at goal.
Two down at the break, the home support might have been dreading the thought of a long second half. Six minutes in, Dundalk had their third when McGinley saved well from a rasping Massey volley, only for Hoban to follow-up and score with the minimum of fuss.
Harps almost pulled one back just before the hour mark when Rogers saved from a Kosovar Sadiki shot after a corner by Barry McNamee, and with the ball having still not hit the ground, Brian Gannon then cleared off the line from Alexander Kogler.
With the contest petering out, Duffy set up the final goal of the night for Slogett on 83 minutes with the former Derry City striker steering home when Sam Todd missed the chance to clear.
Stefan Colovic was unfortunate not to score a fifth Dundalk goal as his pop at goal came back off the Harps post.
Finn Harps: McGinley; McEleney (Coyle, ht), Sadiki, Todd; Webster, R Harkin (G Harkin, 68), Connolly, Russell; McNamee; O'Sullivan (Cretaro, 77), Kogler.
Dundalk: Rogers; Gannon, Cleary, Hoare, Massey; D Kelly (Colovic, 71), Sloggett, Shields, Duffy; Hoban (G Kelly, 79), Smith (McEleney, 76).
Referee: Rob Harvey.