Dundalk lost on their return to the Europa League group stage as Molde came from a goal down to claim a 2-1 victory at Tallaght Stadium in Dublin.
Sean Murray's glancing header gave Dundalk a 35th-minute lead but the Norwegian champions were a much-improved side after the break and Etzaz Hussain's volley which deflected off Darragh Leahy levelled proceedings on the hour.
And the Airtricity League of Ireland champions were denied a share of the spoils for their valiant efforts as Ohi Omoijuanfo scored a 72nd-minute penalty after Sean Gannon had upended Erling Knudtzon in the area.
Molde were able to hang on through eight minutes of time added-on to claim all three points in this Group B fixture.
However, Dundalk can reflect with pride on their performance in their first match back in the group stage of the competition after a four-year absence, when they collected four points in their debut campaign under Stephen Kenny.
Now managed by Filippo Giovagnoli, the hosts made a bright start and had the ball in the back of the net after 24 minutes when Patrick Hoban headed home but the goal was chalked off for a foul in the build-up.
They did not have to wait much longer to break the deadlock. John Mountney's teasing cross was met by the unmarked Murray to nod beyond Molde goalkeeper Andreas Linde.
The visitors had been largely unthreatening before half-time but that changed on the resumption with Dundalk penned back into their own half.
And Molde duly equalised when Marcus Pedersen's pull back to the edge of the area led to Hussain's volley, which took an unfortunate but crucial last touch off Leahy, wrongfooting Dundalk custodian Gary Rogers.
Dundalk were very much on the back foot by this stage and Gannon's foul on Knudtzon, who was tripped after making his way into the area, was followed by Omoijuanfo burying his precision spot-kick.
Rogers guessed the right way but was unable to make any contact, and there was to be no late drama despite a lengthy amount of stoppage time.
