A brace each by Philip Hughes and Keith Dunne secured an impressive win for John Gill’s men to extend their unbeaten run to 18 games.
Dundalk were lucky to see Colin Fortune’s 20-yard effort come back off the upright after just nine minutes.
And the league’s top scorer Philip Hughes helped the Louth club on their way with a superb strike after 15 minutes, his 19th of the season.
The Lilywhites all but sealed the victory a minute after the break when Jim Sheridan saw red for a second bookable offence. From the free kick Sean Finn rolled the ball to Keith Dunne who unleashed a pile driver into the top corner from 25 yards.
Dunne added a second on 78 minutes and Hughes sealed the win two minutes later, making the most of some poor marking to score his 20th of the season.
Chris Bennion. John Flanagan, Brian Kelly, Paul Marney, Robert McAuley, Ray Scully, Robbie Dunne, Sean Finn, Keith Dunne, Peter Hynes (Cathal O’Connor, 55 mins), Philip Hughes.
Danny O’Leary, Ian Rossiter, Kevin Williamson, Des Hope, Jim Sheridan, Colin Fortune, Steve Gavin, Damien Rushe, Eric Lavine, Noel McGee, Padraig Moran (Brian McCarthy, 48 mins).