(CNN)A league game between Greek football giants Panathinaikos and Olympiakos had to be abandoned after 70 minutes on Sunday as fans clashed with both players and police.
Fan violence, firebombs and teargas force Greek derby to be abandoned
Olympiakos, the visiting team at Panathinaikos' Olympic Stadium, was leading the Athens derby 1-0 when German referee Marco Fritz was forced to bring an end to proceedings.
The match was initially stopped for eight minutes within just six minutes of the game kicking off, with a group of home team supporters -- some of whom were masked -- invading the outside of the pitch and attacking the Olympiakos substitutes and those in the team's dugout.
The referee added 13 minutes of first-half stoppage-time to make up for the lengthy incident.
The game's only goal -- scored in the 53rd minute by Spanish striker Miguel Angel Guerrero -- sparked further violence, this time outside the stadium, with fans releasing firebombs.
Police fought back using teargas in an attempt to put an end to the fighting and to regain control. However, the fumes then wafted into the arena and spread onto the pitch, hitting the players and the fans within the stadium.
Some fans then filtered from the stands onto the athletics track around the perimeter of the field.
As a result, Fritz called off the remainder of the game with 20 minutes remaining, with many of the 25,000 Panathinaikos fans who had attended the fixture already having left due to the effects of the teargas.
Olympiakos, who led at the time and continue to chase down PAOK, the Thessaloniki-based club at the summit of Greece's Super League domestic top flight, has been awarded the victory and three crucial points.
Panathinaikos, meanwhile, could face the possibility of a fine and points deduction.
Olympiakos midfielder Kostas Fortounis told his club's official website afterwards: "It's tragic, I cannot explain it.
"Getting into the stadium, chasing the players, our agents... I have no words. After the goal we put in, the fans came on the pitch.
"We could not continue the game. The players of Panathinaikos went to calm them, but they [the fans] were not [calm]."
Panathinaikos also issued a statement, criticizing the actions of a "small minority of 25,000 fans."
Fritz was only in charge after a 2018 ruling decreed that foreign referees would be imported to oversee potentially controversial matches in the nation's Superleague.
This came after FIFA demanded that Greek football made a series of urgent reforms, following a series of unruly, violent incidents.
After a late goal was disallowed in a game between AEK Athens and PAOK last season, PAOK owner Ivan Savvidis stormed onto the pitch armed with a gun. He later received a three-year ban from football and PAOK was docked three points.
A scheduled match between Olympiakos and Panathinaikos' basketball teams on Saturday was forfeited by Olympiakos, who refused to take on its rival without a foreign referee.