The match was marred by a sickening injury to Cork City full-back Brian Lenihan, which saw the game stopped for 10 minutes.
Goals in each half by Steven Beattie and Eoin Wearen at Dalymount Park sealed a deserved victory which, in tandem, prevented City regaining outright leadership at the Premier Division summit over Dundalk.
Cork’s first league loss in nine games may have been painful but not their main concern at the end, given the serious injury sustained by Lenihan that stopped play in the second half.
The full-back landed awkwardly from an aerial challenge against Derek Pender and was eventually taken away by ambulance with his neck protected in a brace.
Bohemians boss Owen Heary kept faith with the same team that drew against St Patrick’s Athletic last time out and it may have contributed to City altering their system to a similar 4-4-2 formation.
Of the front pairings, it was certainly the hosts’ duo Dinny Corcoran and Steven Beattie the more effective in the opening half.
Aside from an early free-kick by Billy Dennehy after two minutes, which Dean Delaney gathered after spilling, Cork were blunt up top.
No such problems afflicted the Gypsies at the other end, and they powered ahead on seven minutes from their first proper attack.
Cork’s defence were caught square from Anto Murphy’s right-wing cross, allowing Beattie to nod past Mark McNulty despite the Cork keeper getting a hand to the effort.
That opener seemed to shock rather than galvanise the title contenders as they almost slipped further behind midway through the half, when Kevin Devaney’s right-foot volley cracked off the crossbar. Beattie wasn’t so pinpoint from the rebound, fizzing a shot wide of the near post with the goal gaping.
It was all going in favour of Bohemians, except on the half hour when referee Neil Doyle ignored a decent penalty claim as Billy Dennehy bundled over Devaney as he raced towards goal.
City struggled to find their usual tempo, illustrated by Cillian Morrison’s lacklustre shot over the crossbar from distance approaching the break.
Heary’s men should have been out of sight well before their second arrived nine minutes before full-time. On the hour, a wicked cross from Paddy Kavanagh found Dan Byrne rising unchallenged in the air, yet he could only nod the ball over.
Chance after chance came the way of Bohemians, with Devaney and Kavanagh threatening in advance of Wearen’s clincher. The former West Ham man pounced to sweep home a right-wing centre by substitute Jason Byrne from close range to bag his second goal in as many games.
Veteran Byrne could even have deepened Cork’s woe in stoppage time only for a superb stop by McNulty after a breakaway move as the visitors became more stretched. For Cork, this is a night they’ll consign to history and hope that their emerging full-back Lenihan gets over the nasty injury he suffered in the second-half.
Delaney; Murphy, D Byrne, Price, Pender; Devaney (Buckley 90+10), Lopes, Wearen, P Kavanagh (Moore 90+8); Corcoran, Beattie (J Byrne 63).
McNulty; Lenihan, D Dennehy, Murray, Davoren (O’Shea 55); C Morrison (Kearney 55), Dunleavy, Healy, B Dennehy; O’Sullivan, O’Flynn (D Morrissey 63).