A derby match between Goztepe and Altay in the Turkish second division was abandoned on Sunday after a fan invaded the pitch and assaulted Altay goalkeeper Ozan Evrim Ozenc with a corner post.
The game was midway through the first half when play was halted to deal with disturbances in the stands as fans clashed and threw flares at the Gursel Aksel Stadium in the city of Izmir.
With two ambulances already deployed to the field and the players distracted, a Goztepe fan charged onto the pitch wielding a corner flag.
The supporter used it to hit the unsuspecting Ozenc twice over the head, shattering the post into pieces.
The fan appeared set to continue the assault before being restrained.
Referee Emre Kargin called both sets of players into the locker rooms and later declared that the match would be suspended with the score at 0-0.
Ozenc was taken to hospital for checks and suffered a 4cm cut in his head as a result of the assault.
Izmir governor Yavuz Selim Kosger later said that those behind the unrest “will be punished with the decision to be taken within the Turkish legal system.”
According to Turkish media, 21 people have already been arrested in connection with the violence.