Dundalk produced a men against boys performance for the second week running to easily see off Derry City in the SSE Airtricity Premier Division clash at Maginn Park.
Stephen Kenny's side were in complete control after they netted four times in the space of 21 minutes in the first half and in truth they could have won by a bigger margin.
Robbie Benson (2), David McMillan and John Mountney netted in a blistering first half display, which meant they could take their foot off the pedal in the second half.
The visitors started on the front foot and had chances in the opening 12 minutes through Michael Duffy and Mountey, but they deservedly took the lead on 23 minutes in sublime fashion.
Mountney's defensive splitting pass found Benson, who ghosted in behind the City defence before lifting the ball over the out-rushing Gerard Doherty.
Dundalk added a second two minutes later as Conor McDermott gifted possession to Patrick McEleney just inside the City half, the midfielder looked up and picked out an inch perfect cross to McMillan, who fired home from 10 yards.
With their tails up the visitors netted a third just after the half hour mark as Duffy's pile driver was parried out by Doherty and Benson was on hand to turn home the rebound.
Just before the break more good play down the left by Duffy ended with his cross finding an unmarked Mountney, who made no mistake drilling the ball low into Doherty's bottom right hand corner.
Stephen Kenny's side were in cruise control after the break but they did have chances with McMillan firing over and substitute Tommy Stewart also having a chance to add a fifth goal, but his strike hit the side-netting, after he had rounded Doherty.
Derry City: G Doherty, McDermott, Cole, Barry, Jarvis; Low, McEneff, McNamee; Schubert (McIntyre 58), Patterson (Boyle 50), Curtis (Dolny 62).
Dundalk: Rogers, Gannon, Gartland, Vemmelund, Massey; Mountney, Shields, Benson (Clifford HT), Duffy; McEleney (Kinsella 70), McMillan (Stewart 62).
Referee: Paul McLaughlin (Donegal).