Bray Wanderers registered their first win of the season at the 11th attempt and heaped further pressure on embattled Shamrock Rovers manager Stephen Bradley at the Carlisle Grounds.
Striker Ronan Coughlan, who had been on trial with the Hoops in pre-season but didn't agree a deal, seized on an over-hit backpass to score the game's only goal.
Rovers played the final half-hour with ten men after striker Dan Carr was sent off for a petulant second yellow card as discipline went out the window on a chilly night in Wicklow.
Bray interim boss Graham Kelly named an identical starting 11 to the one that performed so impressively at home to Dundalk on Friday and deserved better than their 2-0 defeat.
A strong wind blowing towards the home side in the first half gave an indication to how the action would unfold as Rovers dominated possession without ever seriously threatening.
Brandon Miele had the game's first sight of goal after three minutes, when good work from Dan Carr saw the winger into space, but cutting inside on his stronger right foot he scuffed his shot.
Bray lost striker Aaron Greene to an injury midway through the half and they missed his strong running up front when he was replaced by Daniel Kelly, with Coughlan moving up top.
Just before the half-hour, the game had its first shot on target as Miele rattled a free kick from distance that had Aaron Dillon scrambling to palm away at full stretch.
McCabe had a penalty appeal turned down when his shot appeared to rebound off the hand of Ally Gilchrist, but referee Tomás Connolly correctly ruled it to be accidental.
Rovers pushed on as the half approached but were generally short of ideas, with Graham Burke's ambitious 35-yard effort never looking like troubling Dillon.
Burke then bent a shot wide before Boyle squandered a good delivery by the same player when he glanced a header past the post in what was the clearest opening either side had in the first half.
The second half was proceeding along similar lines, but Bray broke the deadlock unexpectedly after eight minutes and it came from a mistake from the unlikeliest of sources.
Hoops captain Ronan Finn overhit a backpass to Gilchrist and Coughlan had a free run on goal before coolly slotting the ball under the advancing Kevin Horgan.
The defensive calamities continued as Finn, ironically, pounced on Lynch's poor back-pass and missed, before Gary McCabe forced a top-class save from Horgan after Gary Shaw's mistake.
Rovers' implosion continued just after the hour mark as Carr – booked early in the half for a bad tackle on Conor Kenna – saw red for a petulant trip to stop Rhys Gorman taking a quick free.
Rovers introduced 17-year-old former Bohemians midfielder Brandon Kavanagh for his league debut and moved to three at the back.
McCabe made immediate use of the extra space, however, and teed up winger Daniel Kelly for a shot that bounced inches wide.
Bray defended stoutly with the wind at their backs, and when Burke blasted a shot just past the top corner, the jig was up for the visiting side.
Bray Wanderers: Aaron Dillon; Dan McKenna, Conor Kenna, Hugh Douglas, Kevin Lynch; Paul O'Conor, Rhys Gorman, Gary McCabe; Ronan Coughlan (Ger Pender 72), Corey Galvin (Jake Kelly 89), Aaron Greene (Daniel Kelly 26).
Shamrock Rovers: Kevin Horgan; Ethan Boyle, Ally Gilchrist, Lee Grace, Sean Kavanagh (Brandon Kavanagh 72); Greg Bolger, Ronan Finn, Graham Burke, Brandon Miele, Joel Coustrain (Gary Shaw 55); Dan Carr.