Mohamed Elyounoussi opened the goalshow with the first two goals—both set up by an inspired Robert Silva. Elyounoussi has now tallied seven goals in the season's first six matches across all competitions.
Only a single two-legged tie against an as-yet-unknown opponent now stands between Bo Svensson's outfit and a spot in the league phase of Europe's third-tier club competition.
Any Hungarian hopes for a dream start that might have injected some suspense into the match were effectively dashed.
Less than three minutes into the game, the skillful dribbler Robert Silva broke through on the left flank. His cross found an unmarked Mohamed Elyounoussi, who simply had to steer the ball home from close range.
Coach Bo Svensson handed a debut to 21-year-old Hungarian centre-back Akos Markgraf during the match. He made a good impression—albeit against limited opposition as Debrecen offered little to threaten the Danish favourites.
The home side dominated the match from the opening whistle, and only a lack of clinical finishing in key moments prevented them from extending their lead before the break.
Their dominance seemed to make the players a bit complacent at the start of the second half. Their play was too slow and their marking too loose, and Debrecen made them pay.
Balázs Dzsudzsák equalised in the 48th minute, before FC Copenhagen tightened their grip and reasserted control over the match.
Promising attacks once again arrived in quick succession, and ten minutes after the equaliser, the home side regained the lead. Elyounoussi converted the penalty won by Robert Silva.
That took the wind out of the visitors' sails. The Hungarians had nothing left to offer, and both Alex Kral and Andreas Cornelius got on the scoresheet in the closing stages of the match—the latter even twice.