Christensen hit a screamer in the 4-1 win as Denmark booked their place in the Euro 2020 round of 16.
The defender celebrated by holding his ears and later explained it was recognition of winning the Champions League with Chelsea.
He explained, "I was just trying to keep the ball down. It worked, and then it looks really good.
"It is an internal joke that runs a bit with me because I won the trophy with the big ears, but it is no longer important."