Cracovia Krakow - Wisla Krakow - 17/10/1943
Source: Wikipedia
During the occupation of Poland in World War II, the Nazi German occupiers banned all sports. However, "illegal" games were played on regular basis. During one of these matches in Kraków on 17 October 1943, fans of Cracovia and Wisła Kraków interrupted the game and started fighting which spread onto the streets of the Ludwinow district in Kraków. The fighting lasted for several hours.