Substitute Kian Leavy got Shelbourne's season up and running with a cracking late winner as Bohemians can only have themselves to blame as they finished with 10 men at Tolka Park.
Declan Devine’s Gypsies, who came into the game top of the Premier Division table, had been the better side until Dylan Connolly was sent off on 67 minutes.
Connolly had burst clear in a counterattack before being stopped by the retreating John Ross Wilson’s superb tackle.
The Bohemians winger got to his feet in frustration before body checking the Shelbourne right-back leaving Northern Ireland referee Arnold Hunter little option but to show him a straight red card.
Shelbourne then won a fitful derby on 78 minutes.
Wilson’s cross was only partially cleared by Kacper Radkowski with the ball falling to Leavy.
The 20-year old Reading loanee cut across Kris Twardek before rifling a crisp low drive to the bottom left-hand corner of James Talbot’s net.
Already set to be without main striker Sean Boyd for some time due to groin surgery, Shels were dealt a further blow pre-match when attacking midfielder Matty Smith was ruled out. Winger Shane Farrell returned in one change from their defeat at St Pat's last week.
Unchanged from their win over Dundalk at Dalymount last time out, Bohemians started with plenty of purpose.
But it was Shels’ more direct approach that brought the first sight of goal six minutes in.
Jack Moylan’s clever feet won a corner which was headed clear, though only to Mark Coyle who got under his first time drive that flew well over the top.
Passing the ball well, Bohemians might have been ahead from their first incisive attack of the game seven minutes later.
Jonathan Afolabi spun Shels skipper Luke Byrne onto Paddy Kirk’s ball down the inside left channel.
Arriving at the far post, Connolly should have found the target from the cross instead of slicing wastefully wide.
It was the 28th minute of a feistily contested derby before we had a first shot on target, Bohemians midfielder Adam McDonnell putting his laces through a loose ball some 30 yards out that was straight into the arms of Conor Kearns in the home goal.
The guile of Moylan soon opened Bohs up again back at the other end, his cross cleared by the well-positioned Grant Horton.
The Bohs defender was then fortunate not to receive a booking for clattering into Evan Caffrey.
Tyreke Wilson’s prowess from a dead ball just hadn’t enough venom on this occasion to punish the visitors as the resulting free kick had the range and accuracy, but not the power to beat James Talbot.
Bohemians enjoyed plenty of the ball on the resumption, but it was almost the hour before they troubled Kearns, Ali Coote coming alive to force a save low down at his right-hand post from the Shelbourne goalkeeper before the real drama arrived in the final quarter.
Shelbourne: Conor Kearns; Paddy Barrett, Luke Byrne, Gavin Molloy; John Ross Wilson, Mark Coyle (Kameron Ledwidge 49), JJ Lunney, Tyreke Wilson; Shane Farrell (Kian Leavy 59), Evan Caffrey (Brian McManus 86), Jack Moylan (Kyle Robinson 86).
Bohemians: James Talbot; Keith Buckley, Grant Horton, Kacper Radkowski, Paddy Kirk (James McMcManus h-t); Adam McDonnell (John O’Sullivan 90), Jordan Flores; Dylan Connolly, Ali Coote (Kris Twardek 70), Declan McDaid (James Akintunde 70); Jonathan Afolabi (Dean Willians 77).
Referee: Arnold Hunter (Northern Ireland).
