Spanish authorities say clashes between supporters of Juventus and Sevilla on Monday night left one Italian fan seriously hurt after he was stabbed and at least three others injured.
Authorities say the fighting began after a group of Sevilla fans attacked the Juventus supporters in the southern Spanish city.
A Marca video shows some of the clashes between the rival supporters, including one fan throwing a chair after stepping outside of the bar. Local police eventually intervened but no arrests were immediately made.
Seville police say the man who was stabbed is in stable condition and his injuries are not life threatening.
Sevilla and Juventus meet at the Ramon Sanchez Pizjuan Stadium in the Champions League on Tuesday.
"I was sat at a table in the Taberna del Papelon bar with my partner and it was around 23:00 when suddenly a group of around 40-50 people, all with their faces covered, came into the bar and made a beeline for a group of young Italians, around 20 of them, all quiet lads who were drinking beer and eating tapas," an anonymous 46-year-old lady is quoted as saying by Gazzetta dello Sport.
"I live in the area and I seem to recognise some of them as Erasmus students in Seville. "All hell broke loose. Tables were flying and bottles were being smashed. The attackers then pulled out baseball bats. I was scared for my life, I just threw myself to the ground. There was blood everywhere, one lad seemed seriously hurt. It all lasted about 10 minutes. One of the waiters was frantic. It took the emergency services a long time to arrive -- about 20 minutes later they got here, even though the bar staff had called the police and ambulance immediately."
It is not the first time this season that violence has occurred ahead of Sevilla's Champions League home games.
On Sept. 27, a small group of Lyon fans clashed with police prior to their game against Sevilla.
On Nov. 2, before Sevilla's game against Dinamo Zagreb, violence flared between opposing fans with several Dinamo supporters arrested by police.
The Associated Press and ESPN FC's Italy correspondent Ben Gladwell contributed to this report