Reporting by Matt Keane
It was a tough night for Waterford as the Lilywhites looked back to their best and took the lead after 8 minutes, as Sean Murray put in a cross from the left and Patrick Hoban headed past the Waterford goalkeeper.
It got worse for the Blues on 36 minutes when Aaron Drinan scuffed an effort in front of goal and seconds later at the other end Maxim Kouogun failed to deal with a long ball and Murray took full advantage to score.
The second half was a similar story, with Daniel Kelly finished off a brilliant move involving several Dundalk players on 57 minutes. Substitute Cameron Dummigan completed the rout in the dying minutes.
Elsewhere last night in the SSE Airtricity Premier Division round of fixtures, James Finnerty's strike 14-minutes from time at home to Derry maintained Bohemians' unbeaten start to season.
Keith Long's side played out a 1-1 draw with the Candystripes at Dalymount Park, under the gaze of Republic of Ireland boss Mick McCarthy.
But Shamrock Rovers top the table with Aaron McEneff's early penalty enough to give them a 1-nil win over St. Pat's at Richmond Park.
Game of the night was in Ballybofey where Finn Harps twice took the lead, but were eventually beaten 4-3 by Cork City.
