Hundreds of fans from Istanbul football club Fenerbahce have clashed with Turkish police and occupied the pitch after a title match.
Police used pepper spray to disperse fans as players fled to changing rooms.
The team's traditional rival, Galatasaray, won the Turkish league championship following Saturday's goalless derby.
Galatasaray fans celebrated elsewhere in the city, dancing, lighting flares and waving their flags.
Fans broke plastic chairs and threw them at the police after the final whistle. Flares were also thrown.
The violence followed a tense game during which referee Cuneyt Cakir booked several players and issued red cards to one player from each team.
While journalists, players and even policemen were said to have been affected by pepper spray, there were no reports of injuries.
Galatasaray ended the four-way title play-offs with 48 points, one ahead of Fenerbahce. Trabzonspor were third and Besiktas fourth.
Galatasaray, former Uefa Cup winners, are now level on 18 championships with Fenerbahce.