A Greek Cup second-leg tie between AEK Athens and Olympiakos was suspended in the 90th minute on Wednesday after crowd trouble.
According to Reuters, groups of AEK fans stormed the pitch after Olympiakos took a 1-0 lead in the 89th minute, a goal which gave them the advantage in the tie.
Match officials and players of both teams immediately left the pitch before police moved in to confront the fans.
No decision has been made on whether the game will be resumed or abandoned.
The event marks the latest in a string of unfortunate incidents involving Greek clubs, with the Greek Super League having been forced to halt matches three separate times already this season.