Violent clashes leaving one fan in a critical condition and dozens injured overshadowed Thursday's Europa Conference League game between Nice and Cologne in southern France.
One hour before the scheduled kick-off of the opening match in the third-tier European competition at the Allianz Stadium several hundred hooded fans in the Cologne colours invaded the stand of Nice fans.
The rivals came to blows, some armed with chairs or iron bars torn from the stadium.
A total of 32 people were injured, including two police officers and a steward, and four hospitalised, with one, a Parisian who had been among the German supporters, in a "critical condition" after falling in the mayhem.
"The man fell five meters between the first and second level of the stands. The accident occurred after the incidents in the stadium," Benoît Huber, director of office of the prefect of the Alpes-Maritimes, told AFP.
Faced with these incidents, the gates of the stadium were temporarily closed with the game pushed back nearly an hour.
The Group D game eventually kicked off ending in a 1-1 draw with Steffen Tigges opening for the visitors after 19 minutes before Andy Delort earning a point from the penalty spot after an hour.
"It's disappointing, infuriating to see that," said Nice coach Lucien Favre of the violence.
"It shouldn't happen. One more person got seriously injured. We weren't even sure if we were going to play. But I think we had to play this match.
"Our supporters have nothing to reproach themselves with, a stadium ban would be too unfair."
Meanwhile Favre extended his condolences to the club's English owner Jim Ratcliff after the death of Queen Elizabeth II, who he said "had a big impact on us".
Meanwhile a minute’s silence was held before the games of British teams West Ham and Hearts.
West Ham came from behind to beat Romanian side FCSB 3-1 in their Group B opener after Andrei Cordea put the Romanians ahead after 34 minutes.
Jarrod Bowen pulled the English side back from the penalty spot after 69 minutes following a foul on Maxwel Cornet with Emerson adding a second with quarter of an hour to go and Michail Antonio scoring the third late.
Scottish side Hearts fell 4-0 at home to Istanbul Basaksehir.