The leading scorer in the competition so far had to wait for Copenhagen to net first before he got off the mark, but did so just before the half hour mark by nutmegging a defender and planting the ball calmly in the back of the net.
Goals from Maxi Rolon and Elohor Godswill gave Barcelona a comfortable lead before El Haddadi scored a final-minute stunner as he ran 50-yards down the right hand side before applying the perfect finish to round off the Catalan side’s night.
The 18-year-old is rumoured to have a 12 million euro release clause in his contract but will stay with the Spanish side until 2017 at the earliest. Arsenal are rumoured to be interested.
The rest of the second round fixtures from the UEFA Youth League take place next week.
Watch below highlights from last night’s encounter.