Hopes of retaining their league title have taken a real battering at Dundalk since the 2020 season resumed last week, the Lilywhites potentially eight points off the lead by tomorrow after this defeat.
And Dundalk boss Vinny Perth admits his side had no excuses as early goals from Danny Grant and Keith Buckley, both inspired by the sublime Kris Twardek, gained Bohs the win they needed to push them into second place in the table, Michael Duffy with the only response from Dundalk.
"It would be wrong to say we got anything more than what we deserved," said Perth, his side with a poor return of one point from two games since the league resumed.
"There are no excuses for that performance, it's not good enough.
"Momentum is huge and when you get to the top, it's very easy to get knocked off and we have been knocked off.
"We have to get our momentum back as quickly as possible. It's a big week coming up for us," added Perth, his side facing into FAI Cup and league action next week after tomorrow's draw for the Champions League qualifiers.
Grant and Buckley got the goals for the home side but the plaudits must go to Canadian import Twardek, who had a hand in both of them and was a constant threat to the champions and full-back Seán Gannon, in particular.
The impressive Twardek was unfortunate not to nab a goal for himself. "Kris has done really well, we are really pleased with him, he's a good guy, very honest, a good professional, he works really hard and is very diligent at his job," said Bohs boss Keith Long. "I can't speak highly enough of him."
Already behind Shamrock Rovers in the standings ahead of this game, the pressure was on Dundalk and yet they were slow to start, being 2-0 down after just 15 minutes. On seven minutes, Twardek did well out wide. He fed the ball to left-back Anto Breslin and his cross was met in the box by a header from Grant which beat Gary Rogers in the Dundalk goal.
In the 15th minute, Bohs had doubled that lead. More good work by Twardek saw him beat Gannon and whip in a cross. Keith Ward laid the ball off to captain Buckley and he struck home his first goal of the season.
Sub John Mountney, on for Daniel Kelly, made Dundalk look a bit more composed, though, and they got back into the game three minutes before the break, with a goal from Duffy. Stefan Colovic was the creator, a fine cross from the Serbian headed home by Duffy.
And Dundalk looked strong after the restart, a double save from Bohs 'keeper Stephen McGuinness denying Pat Hoban and Mountney, but the home side, who have won both their games since the league restarted, remained a constant threat. Dundalk pressed hard for a second goal but could find no way past McGuinness.
BOHS - McGuinness; Lyons, Cornwall, Casey, Breslin; Lunney, Buckley; Grant, Ward (Devoy 71), Twardek; Wright.
DUNDALK - Rogers; Gannon, Cleary, Boyle, Massey (Oduwa 86); Shields, Flores (Patching 65); Kelly (Mountney 33), Colovic, Duffy; Hoban.
REF - N Doyle