It's now seven wins and a scoreless draw from eight games for Bohemians against their old rivals, as Shamrock Rovers' title challenge looks in ribbons after another night to forget in Dalymount.
In truth, they had most of the ball, but that matters for nothing when self-destruction never seems far away for the Hoops in this riveting series of Dublin derbies.
Bohs may not win the league but they can reflect on another incredible night in which they had a mental edge over Stephen Bradley's men.
Daniel Mandroiu, the Bohs' playmaker's fired home a brace, including an outrageous winner will have British scouts purring over the Irish youth international. A sublime Dan Carr finish in between not enough for the beleaguered visitors.
They enter the break thinking of a must-win Tallaght tussle against Dundalk, whose players will go on camp in Spain next weekend with half an eye on Europe and the other on a title challenge that is theirs to lose.
Bohs, with three of their starting back four absent and Dinny Corcoran out for the season, had to shuffle their pack.
However, they looked full of confidence in the warm-up, manager Keith Long playing one-twos with some of his players in front of goal.
Rovers had few injury concerns and arrived bereft of excuses. However, they struggled to get their passing game going in the first half.
A rip-roaring opening in front of a baying home crowd saw Bohs start with vigour, but Rovers looked threatening on the break. Indeed, excellent Hoops play fashioned the first chance on six minutes.
Jack Byrne and Dylan Watts were heavily involved before Carr pulled the ball back, only for Greg Bolger to slice his effort wide on his weaker foot. Both of the penalties they conceded were a shambles from a Rovers perspective.
Byrne left a needless foot in on Kevin Devaney from a Bohs free-kick and he went down, forcing referee Rob Rogers to point to the spot.
However, Alan Mannus produced an amazing save from Danny Mandriou, diving to his right at full stretch. One sensed Rovers would now go on and take control and they enjoyed an initial boost.
Carr's header from a superb Byrne corner had a fully stretched Andy Lyons head off the line on 18 minutes. Byrne, outstanding so far, was passing the ball with immense precision and fashioned space a minute later but his shot went wide.
Rovers gave away another crazy penalty midway through the half. Bohs had a high press on their rivals' kick-outs again and it paid off.
Ethan Boyle played a suicidal pass to Bolger at the edge of the box and the Wexford man, without much time to think about it, failed to reach the ball but instead upended Ryan Swan.
Mandriou, with no hang-up from his miss, put Mannus the other way. There were 24 minutes played.Rovers rallied and James Talbot, fresh from time with the Irish squad, produced a superb double-save on 36 minutes.
Sweet Rovers interplay put Aaron Greene in and, after his strike was parried by Talbot, he smothered out Dylan Watts' rebound.
Watts, facing his former club, forced a brilliant save from Talbot as half-time approached, Rovers on top. Boyle then headed wide when he should have scored.
Rovers equalised six minutes into the second half and it was route-one stuff, with Bohs appealing for a free-kick to no avail. Ronan Finn showed brilliant technique when he flicked on to Carr, who produced a delightful dinked finish on the volley in off the post. Bohs went back in front on the hour-mark through Mandriou.
Unperturbed by having the ball on his left-foot, he lashed a half-volley in from about 25 yards that left Mannus reeling. Buckley then put Ward through and his left-footed shot was cleared away, Rovers reeling.
The visitors were still very much in it, Carr heading wide from Bolger's enticing cross with 20 minutes left.With half an hour of the second half gone, Rovers broke and Greene found Bolger at the edge of the box but, after he teed up Byrne, the former Manchester City youth blazed over.
Bohs finished strongly and an outrageous melee in the box saw Mannus save from Mandriou and former Gypsies defender Pico Lopes clear off the line twice, the home crowd looking for a handball and the final insult.
Eight minutes of injury time then gave the visitors some hope.There was none, despite some valiant late attacks, and a major challenge awaits Bradley's men to see how they can rally from this.
Bohemians: Talbot, Lyons, Barry, Barker (Ward 56), Kirk, Devaney, Wade-Slater, Buckley (McCourt 90), Levingston (Allardyce 46), Mandriou, Swan.
Shamrock Rovers: Mannus, Boyle, Grace, Lopes, Clarke (S Kavanagh 62), Carr, Byrne, Bolger, Watts, Finn, Greene.Referee: Rob Rogers.