Violence in the stands and two pitch invasions forced the abandonment of Sunday's Greek Super League derby between Panathinaikos and Olympiakos at the Athens Olympic Stadium.
German referee Marco Fritz called off the match in the 69th minute with Olympiakos leading 1-0 and with chaotic scenes unfolding inside and outside the ground.
Riot-trained police used tear gas to bring order and to chase away dozens of hooligans who had darted on to the field.
The match was interrupted first in the fifth minute of play when a few fans entered the pitch and police managed to usher them back into the stands. Fritz then waited a few minutes before play resumed.
But in the 69th minute and with clashes already occurring between fans and police in the stands, security personnel were overwhelmed by dozens of hooligans, forcing Fritz to order the players off the pitch and into the dressing rooms.
Fritz had called for the stadium of about 25,000 spectators to be evacuated in order for the match to continue with the visitors in the lead. But one hour later he came out to observe that spectators were still present and then called off the match.
Panathinaikos now face the prospect of the match being awarded to Olympiakos, a deduction of six points from the standings and a heavy fine.