Gary Shaw’s early goal heaped more misery on Dundalk as Shamrock Rovers left Oriel Park with all three points on Sunday.
After making their exit from the Europa League during the week, this victory could go a long way to ensuring that the Tallaght side will be back in the competition next year.
Shaw’s sixth goal of the campaign moves Stephen Bradley's side into third place, one point ahead of Derry City and two ahead of Bray Wanderers, in the automatic qualification places.
Dundalk remain in second, 11 ahead of the Hoops, but with their Champions League hopes ended by Rosenborg in Norway last Wednesday night, and the league title heading south to Cork, the two domestic cups are all that remain for Stephen Kenny’s side to collect.
They looked sluggish throughout and were left to rue a missed opportunity after just 30 seconds of play.
A clearance from the back found its way to Dylan Connolly who surged into the Rovers penalty area but his goal bound effort was brilliantly pushed behind by Tomer Chencinski.
Rovers hit back and edged in front with their first chance of the game after five minutes. Ryan Connolly picked out Shaw on the edge of the Dundalk penalty area and the striker turned Brian Gartland to bury his effort past Gary Rogers.
Dundalk struggled to go through the gears and Brandon Miele almost made Paddy Barrett pay for a sloppy pass, the Rovers' number 10 lashing an effort just past the upright.
The League of Ireland champions looked like they were beginning to build a head of steam when Michael Duffy guided a curling attempt just off target.
David McMillan did likewise shortly after, pulling his effort wide under pressure from Dave Webster after a neat set-up by Connolly.
Their best opening of the half arrived in the 38th minute.
Stephen O'Donnell rolled a free-kick to Connolly and he picked out the run of Barrett at the far post only for the defender to hook the delivery wide.
Rovers probed and controlled the second half and Rogers needed to get a solid hand on a Dave Webster header and a Brandon Miele snapshot to keep Dundalk in the game.
O'Donnell and substitute Thomas Stewart both had half chances late on but the expected Dundalk onslaught never arrived and Rovers never looked in danger of giving up their early lead and held on for a well-earned win.
Dundalk: Gary Rogers; Sean Hoare, Brian Gartland, Paddy Barrett, Dane Massey; Robbie Benson, Stephen O’Donnell; Dylan Connolly (John Mountney 75), Jamie McGrath (Thomas Stewart 60), Michael Duffy (Ciaran Kilduff 77); David McMillan.
Shamrock Rovers: Tomer Chencinski; Simon Madden, Dave Webster, Roberto Lopes, Luke Byrne; Ryan Connolly, David McAllister; Trevor Clarke (Sam Bone 86), Graham Burke (Sean Boyd 89), Brandon Miele; Gary Shaw (Michael O’Connor 90).
Referee: Rob Rogers.
