Bohemians moved off the bottom of the Premier Division table as Dave Mulcahy’s early goal gave them a 1-0 win over Dublin rivals Shamrock Rovers.
Mulcahy’s close range strike after three minutes and defeats for Shelborne and Bray Wanderers mean Bohs moved out of the bottom two.
Rovers missed the chance to equalise with ten minutes left as Ronan Finn smashed his penalty kick off the crossbar.
The victory was Bohs’ first at Dalymount Park since late April and they had only won once in the intervening four months.
The defeat puts more pressure on Rovers boss Trevor Croly and all but ends their hopes of earning a European place through the league this season.
This fiercely contested derby may have been overshadowed by games in the title race elsewhere, but it had huge significance for Bohs as they try to avoid the drop and it showed in how they approached the game.
Owen Heary was dealt a blow earlier in the day when Ryan McEvoy pulled out with a throat infection, meaning Daniel Byrne made his first senior start in midfield.
The visitors, who were without several players through injury and suspension, welcomed back Eamon Zayed from international duty, but he had to be content with a place on the bench.
Rovers were caught out early as Mulcahy put Bohs in front in the third minute when he finished off a training ground move.
Andy Mulligan’s low corner was dummied by Anto Murphy into the path of Luke Byrne. The shot was scuffed, but Mulcahy was alert to steer the ball into the net.
Rovers almost had the perfect riposte within two minutes when Danny Ledwith’s curling free-kick hit the post and rebounded out.
Hefty challenges from Anto Murphy on Shane Robinson and Mulcahy on Conor Powell served to enliven an already raucous atmosphere. Skipper Mulcahy was excelling in the midfield battles, as well as playing a key defensive role.
Finn twice went close for the Hoops in the first half. First, with a header from a Ledwith delivery and then with a low strike after Bohs failed to clear Ledwith’s corner.
The home side were fortunate not to concede a penalty just before the break when Anto Murphy blocked Robinson’s shot with his hands. Referee Padraig Sutton ruled it was accidental and waved away Rovers’ appeals.
A positive start to the second half from Rovers saw Karl Sheppard leap highest at the back post to head Ledwith’s cross goalwards. Dean Delany reacted well to get down and parry to the ball away.
Bohs weathered the storm and could have extended their lead as Dinny Corcoran’s ball put Mulligan through. The winger’s shot beat Barry Murphy and they could only watch as the ball rolled wide of the far post.
Finn was given the opportunity draw his side level on 80 minutes after Derek Pender handled in the area. His spot-kick was well struck but rattled off the bar.
Bohs withstood some sustained pressure in the final ten minutes, but held on for the confidence-boosting win to the relief of the home fans.
Bohemians: Dean Delany; Derek Pender, Roberto Lopes, Anto Murphy, Luke Byrne; Lorcan Shannon (Keith Buckley 54), Dave Mulcahy, Daniel Byrne, Andy Mulligan; Conor Murphy (Stephen Traynor 60), Dinny Corcoran (Dave Scully 84).
Subs not used: Darragh Reynor, Kevin Devaney, Michael Barker (20 today), Greg Murray.
Booked: Mulcahy, Luke Byrne, Pender.
Shamrock Rovers: Barry Murphy; Conor McCormack, Pat Sullivan, Ken Oman, Conor Powell; Richie Ryan; Gary McCabe (Thomas Stewart h/t), Shane Robinson (Eamon Zayed 84); Ronan Finn, Danny Ledwith (Mark Quigley 65); Karl Sheppard.
Subs not used: James Chambers, Nathan Brown, David Elebert, Shane Fagan.
Referee: Padraig Sutton.