Looking refreshed from a week off, Bohemians got at Dundalk from the first whistle with Ryan McEvoy testing Peter Cherrie with a 20-yard volley in the second minute.
Karl Moore then cut across from the right on 11 minutes to unleash a left-foot strike that stung the palms of Cherrie as he parried it away. The ball then ricocheted off Owen Heary and was flicked wide by Dwayne Wilson.
Captain Heary then forced an agile, tip-over save from Cherrie with an audacious effort with the outside of his right foot.
Dundalk lost midfielder John Mountney to injury on 31 minutes and found themselves a goal down four minutes later. Peter McMahon’s diagonal ball picked out Heary whose header bounced through to the net with what appeared the slightest of touches from fellow defender Evan McMillan.
If there was a doubt about who was claiming that goal, McMillan ensured there was no dispute about Bohs’ second in the first minute of added time at the end of the half as the big central defender met Keith Ward’s corner to score with a stooping header.
Dundalk had a little more purpose about them in the second half and got a goal back with their first shot on target in the 70th minute.
Mark Griffin touched a free kick to Michael Rafter who drilled a fierce shot low to the corner of the net from some distance.
BOHEMIANS: McNulty; Heary, McMillan, Feely, Byrne; Barker McEvoy, Ward (Mulcahy, 73); Moore (Buckley, 81), Wilson, McMahon (Mulligan, 59).
DUNDALK: Cherrie; Gaul (Woods, 90), Foran, Shields, Murphy; Waters (Thomas, 55), McDonnell, Shanahan; Griffin, Rafter, Mountney (Walsh, 31).
Referee: Graham Kelly (Cork).