Borussia Moenchengladbach may have to answer quite a few questions after the Rhine derby against Cologne on Saturday in the Bundesliga.
Swiss international Granit Xhaka headed home a 91st minute winner to snare the host the three points, but after the final whistle things turned nasty.
A group of around 30 Cologne thugs, many dressed in white boiler suits, broke onto the pitch as the Gladbach players were saluting their supporters.
Riot police soon entered the fray, and many of the Cologne pitch invaders fled the scene instantly.
Fan footage recorded much of the action, including the moment that a group of Cologne idiots fled police by running towards a section housing Gladbach fans. When they got there they came under a barrage of kicks and punches from the home supporters.
Noticeably, men wearing official looking green jackets, looking like security, stood very close to the incident appeared to do very little to stop the attack, even allowing one Gladbach fan to punch a guy repeatedly after two green jacketed men had him constrained.