Reporting by Matt Keane.
The visitors were dealt a blow after 27 minutes when Mark Coyle picked up a second yellow card for a nasty foul on Shane Duggan, leaving them with 10 men for the remainder of the match.
The Blues took the lead 5 minutes before the half time break when Aaron Drinan headed home a Rory Feely cross.
Drinan added a second on 66 minutes, and less than 10 minutes later Shane Duggan made it 3-0.
Two substitutes combined to complete the scoring on 90 minutes, with Izzy Akinade the supplier for local striker Dean Walsh.
It finished Waterford FC 4 Finn Harps 0.