Harps made extensive changes for this visit to the Brandywell as Jamie Bell, Jack Doherty and Kieran Farren all made their first debuts for Harps.
An early brace from Junior Ogedi-Uzokwe meant the game was never in much doubt, as the league's top scorer notched his first following a through ball and his second following a through corner. Harps were rocking at that stage, but the score remained 2-0 at the break.
Harps started the second half in more positive fashion and made chances for Walsh, Deasy and Logue but could not manage to reduce the deficit.
Ogedi-Uzokwe was on the mark once more on 64 minutes and Grant Gillespie added a fourth not long after to settle matters at the Brandywell. For Harps the focus is now firmly on the promotion relegation playoff where Drogheda United await.
The away leg takes place on Monday night at United Park before the season reaches its climax with the home leg in Finn Park next Friday night. Tickets will be in the usual outlets for the home leg early next week, while we will post information for Harps fans travelling to Drogheda as soon as possible.
Derry City: Peter Cherrie; Grant Gillespie, Eoin Toal (Mark McChrystal 75), Ally Gilchrist, Ciaran Coll; Jamie McDonagh (Aidy Delap 68), Greg Sloggett, Ciaron Harkin, Junior Ogedi-Uzokwe; Barry McNamee (Michael McCrudden 79); David Parkhouse.
Finn Harps: Jamie Bell; Colm Deasy, Keith Cowan (Joshua Smith half-time), Niall Logue, Daniel O’Reilly; Shaun Doherty (Jack Doherty 78), Stephen Doherty, Kieran Farren; Tony McNamee (Mark Coyle 67); Liam Walsh, Mikey Place.
Referee: Derek Tomney.