Molde turned on the style in the second half as two goals in 10 minutes denied Dundalk a dream start to their Europa League Group B campaign at Tallaght Stadium.
Sean Murray's third European goal in as many matches had Filippo Giovagnoli’s side deservedly in front at the break.
However, the Norwegians up the ante in the second half with a deflected Etzaz Hussain strike and a Ohi Omoijuanfo penalty seeing Erling Moe's escape with the three points.
It was probably no more than the visitors deserved over the course of the game but Filippo Giovagnoli’s side gave a good account of themselves on the night and will bemoan a disallowed goal by Patrick Hoban in the first half that looked harsh in the extreme.
They will now travel to face Arsenal at the Emirates Stadium next Thursday but not before a crucial league match away to Waterford FC on Sunday.
The Louth men started well, controlling possession and limiting the threat of their visitors.
It took until the 16th minute for the first chance of note to arrive, however, when Mountney drilled a free kick to the left and wide.
Dundalk were then unlucky not to take the lead on 24 minutes when they had a goal rather harshly chalked off by referee Petri Viljanen. After Michael Duffy's cross from the left was headed straight up in the air by Kristoffer Haugen, Hoban appeared to have outmuscled Martin Bjørnbak to head to the net but the Finnish official instead awarded a free out.
The first real scare for the home side came on 33 minutes when Magnus Wolff Eikrem’s corner was headed clear by Hoban only as far as Marcus Holmgren Pedersen who flashed a shot just wide.
The breakthrough would then arrive for Dundalk two minutes later. After good link up play on the right by Sean Gannon and Mountney the latter delivered a peace of a cross which Murray raced onto to glance past Andreas Linde.
After 560 days without a goal the midfielder had now scored four big ones in the last 29 days.
Pedersen would have two further attempts well off target before the break but neither had the accuracy to trouble Gary Rogers.
The visitors had much more about them on the restart and almost pulled a goal back on 55 minutes after a sustained period of pressure.
Rogers did well to punch clear Eikrem’s cross under pressure from Stian Gregersen but the defender almost scored in fortunate circumstances moments later when Mathis Bolly’s follow up deflected up off him and over the bar.
The equaliser arrived on 62 minutes with what was Molde’s first shot on target. Pedersen found space on the right to cross to Hussain, whose left foot volley deflected to the net off Gannon.
The Eliteserien champions would then take the lead on 72 minutes with Omoijuanfo firing a penalty into the bottom left hand corner despite Rogers going the right way after Gannon had fouled substitute Erling Knudzton in the box.
Giovagnoli emptied his bench after that with David McMillan, Andy Boyle, Cameron Dummigan and Stefan Colovic all introduced but despite late pressure they failed to threaten Linde.
Dummigan did have a shot deflected into team-mate Brian Gartland before fellow centre half Daniel Cleary was unable to control a cross from Mountney.
Dundalk: Gary Rogers; Sean Gannon (David McMillan 77), Brian Gartland, Daniel Cleary, Darragh Leahy (Cameron Dummigan 77); Chris Shields, Greg Sloggett (Patrick McEleney 64); John Mountney, Sean Murray (Andy Boyle 77), Michael Duffy (Stefan Colovic 79), Patrick Hoban.
Molde: Andreas Linde; Marcus Holmgren Pedersen, Martin Bjørnbak, Stian Rode Gregersen, Kristoffer Haugen; Fredrik Aursnes, Magnus Wolff Eikrem (Martin Ellingsen 82), Etzaz Hussain; Eirik Hestad, Ohi Omoijuanfo (Ola Brynhildsen 95), Mathis Bolly (Erling Knudtzon 69).Referee: Petri Viljanen (Finland).