FC Copenhagen on Monday evening left Haderslev with a 2-0 victory, following a match that was effectively decided before halftime.
Felix Beijmo and Andreas Cornelius scored the goals, which essentially extinguished any suspense in the Superliga encounter.
The hosts were without head coach Fatah Abdirahman on Monday, as he remained at home due to illness. However, according to stand-in Simon Poulsen, Abdirahman had still determined the starting lineup for the passive Sonderjyske side that took the pitch.
The visitors were afforded plenty of time and space to break through the Sonderjyske defense. While it did not result in a barrage of chances, it was enough to establish the necessary lead.
After 20 minutes, Felix Beijmo struck a volley toward Marcus Bundgaard, who could not prevent the ball from hitting the back of the net despite striking his leg.
Five minutes before the break, there was little he could do when Cornelius made a sharp turn and placed the ball past the keeper with great precision.
Sonderjyske attempted a tactical shift during the match and quickly managed to create a couple of chances. First, the otherwise in-form Osaze de Rosario fired wide of the goal, and a few minutes later, Ismail Seydi was denied by Copenhagen goalkeeper Diant Ramaj following a strong run.
Instead, Cornelius had a couple of great opportunities to put the game to bed. First, he struck the ball poorly during a counter-attack around the hour mark, and a little later, he was unable to even get a shot off before Alexander Munksgaard managed to poke the ball away inside the box.
But the visitors could still return to the Danish capital with the three points.