- Fans clashed with police
- "Kettled" around Madrid throughout the day
- Many traveling supporters missed kick-off
WHAT HAPPENED? The German club's supporters were reportedly "kettled" around the streets of the Spanish ahead of their team's Champions League debut against Real Madrid. Videos showed fans clashing with police and forced to move through tight areas. Footage shows a large group of supporters still waiting outside the stadium as the Champions League anthem played before kick-off.
THE BIGGER PICTURE: Union fans crowded the streets peacefully for hours in advance. The German club are appearing in the Champions League for the first time after finishing fourth in the Bundesliga last year.
IN TWO PHOTOS:Getty ImagesGetty Images
WHAT NEXT? After Wednesday's clash, the two sides will return to league play. Union Berlin will host Hoffenheim, while Madrid will make the short trip to the Wanda Metropolitano to face Atletico.