With their third win in four games, Shelbourne re-affirmed their title credentials with this dismissal of a struggling Dundalk side. The first goal came after 10 minutes. Davy Byrne released Dessie Baker down the inside-right channel. Baker's cross drew John Connolly off his line and Stephen Geoghegan stretched to tap home his fifth goal in four games.
Dundalk settled and enjoyed good passages of possession without really threatening the Shelbourne goal. The real difference in the sides was witnessed when they got forward, with the home side always likely to score.
Connolly's goal was breached again five minutes before the break. Pat Fenlon and Geoghegan combined to play in Jim Crawford and he calmly side-footed past the overworked Connolly.
Martin Reilly, who shot wide, and David Ward, who shot straight at Williams, wasted two glorious chances to get Dundalk back in it within 15 minutes of half-time.
Jim Gannon added Shelbourne's third when converting Jonathan Minnock's cross from the left on 63 minutes. Davy Byrne then added the fourth four minutes later after a blunder by Connolly.
Dundalk had Liam Dunne sent off for a second bookable offence 15 minutes from time.
SHELBOURNE: Williams; Heary, Doherty, McCarthy, Minnock; Gannon, D. Byrne, Crawford; D. Baker, Geoghegan, Fenlon. Subs: B Byrne for Fenlon (61 mins), Houlihan for Geoghegan (71), P Byrne for D Byrne (84).
DUNDALK: Connolly; Melvin, Broughan, McGuinness, Hoey; Prizeman, Dunne, Kavanagh, Ward; Reilly, Ryan. Subs: Keddy for Prizeman (h-t), Robinson for Ryan (59 mins), Flanagan for Broughan (71).
Referee: J Stacey (Athlone)