After the visitors grabbed the initiative in the opening stages, the first 45 minutes were characterized by two teams that did not dare to risk too much with chances few and far between.
Shortly before the end of the first half, the tide seemed to turn in FC Copenhagen's favour when Tobias Salquist blocked a decisive delivery from Mohamed Elyounoussi and subsequently was sent off.
The home side, however, didn´t lose belief and took a shock lead shortly after the break, when Sindre Walle Egeli laid the ball into the path of Prince Amoako Junior, who slotted the ball past FC Copenhagen keeper Dominik Kotarski.
Despite many chances, the newly purchased Youssoufa Moukoko, who arrived in the Danish capital from Borussia Dortmund, had failed to deliver until today, but the former German international finally found the net after 59 minutes when he directed a header past William Lykke to bring the match back on equal terms.
15 minutes from the end Pantelis Hatzidiakos put the visitors ahead when the ball landed at his feet following a free-kick from Magnus Mattson and the Greek defender scored easily from short range to put the visitors in solid control.
In injury time Yoram Zague scored his first goal for Jacob Neestrup's side to put the game finally beyond reach for the home side to seal top spot for the visitors.
In the other game of the round FC Fredericia recorded their first win of the season thanks to a last-gasp matchwinning goal from Agon Mucolli in a 3-2 win against Sonderjyske who had Ebube Dure sent off after 33 minutes.