Drogheda started on the front foot, however. Ryan McEvoy shot over the bar from long range in the third minute and Stephen Dunne fired over from a short corner in the 13th minute.
Dundalk threatened on several occasions but timely interventions by Killian Brennan, Colm Deasy, and Ciaran McGuigan denied the visitors shooting opportunities.
With half an hour gone there was no sign of the flurry of goals to come, but then Drogheda teenager Thomas Byrne launched into a late challenge on Patrick McEleney right in front of the Dundalk dugout and referee Derek Tomney pulled out the red card.
Then in an eight-minute spell coming up to half-time, Dundalk helped themselves to three goals with their first three attempts of the match.
The first, on 36 minutes, came from a 25-yard shot by Stephen O’Donnell which keeper Stephen McGuinness parried into the path of David McMillan who tapped home.
McMillan bundled the ball home again from almost on the goal-line to give Dundalk a two-goal cushion after Niclas Vemmelund dinked the ball into the six-yard area.
The Lilywhites effectively put the game to bed on 44 minutes when McEleney spotted McGuinness slightly off his line and chipped a superlative effort into the top corner.
Just before the hour mark McGuinness was picking the ball out of the net for a fourth time when Stewart neatly teed up Duffy in the box and the former Celtic man lashed a shot beyond the Drogs keeper.
Ciaran Kilduff beat McGuinness at his near post for 5-0 on 83 minutes and almost immediately Kilduff was put through again to slot home for Dundalk’s sixth.
McGuinness; Deasy, Gallagher, McGuigan, Dunne; McEvoy, K Brennan; Wixted, S Brennan, Byrne; Masterson.
Thornton for K Brennan (46min), Elliott for Masterson (73min), Doyle for S Brennan (90min).
Rogers; Gannon, Gartland, Vemmelund, Massey; Benson, O’Donnell; McEleney, Stewart, Duffy; McMillan.
McGrath for Duffy (62min), Kilduff for McMillan (73min), Shields for Benson (77min).
Derek Tomney (Dublin)