While Germany and Denmark were battling it out in their Euro 2024 last-16 clash, police had to deal with a man who had somehow made it onto the stadium's roof during the encounter.
Officers managed to bring the 21-year-old back down and arrested him, police said in a statement late on Saturday.
A helicopter illuminated the roof of the Westfalenstadion while officers approached the man, it said.
The man is from the north-western German city of Osnabrück, police said in an update on Sunday morning.
According to police, he had made it onto the roof at 10.27 pm (2027 GMT). It was initially unclear how he had gotten up there and to what end.