Ålborg's Swedish goalkeeper Jacob Rinne failed to box the ball away in the 81st minute and then Claesson appeared - 20 minutes after his inning - and put his forehead to the ball and it was 1-0 to visiting FCK, which was the end result.
After the match, Claesson was highlighted by teammates to receive the cheers of FCK fans.
- It was a perfect situation to get in, it was 0-0, both went for the victory.
I think we have a good view of the last 20, 25 and we eat them.
1-0 is not unfair in the end, it's nice to be able to decide directly in front of their fans as well.
It can not get better than that, he tells Viaplay.
FC Copenhagen tops the table, nine points ahead of FC Midtjylland.
Claesson's contract with FC Copenhagen applies until the spring season.