Police in northern Greece say 22 people have been arrested after basketball fans went on the rampage, damaging property and clashing with supporters from rival teams.
The violence early Thursday involved several hundred fans of PAOK Thessaloniki after they were expelled from a game against Olympiakos.
Olympiakos won the Greek Cup semifinal playoff 79-60, but only after the game late Wednesday was interrupted by violence for more than two hours.
The rioting supporters clashed with riot police and rival fans, and smashed supporter clubs of city rivals Aris and Iraklis, according to police.
Those arrested were to be charged with public order offenses.