The Argentine second division was rocked after Alejandro Roncaglia, brother of Fiorentina defender Facundo Roncaglia, knocked out referee Arnaldo Beron when he was shown a yellow card.
Roncaglia reacted angrily after he was booked by referee Beron in the match between Ferro and Tiro Federal.
Beron was knocked out by Roncaglia, who had to be restrained by team-mates, when the player disapproved with the referee's decision.
Players quickly rushed to Beron's aid and called for medical help as the referee laid motionless on the pitch.
The match was abandoned as the referee had to be taken to hospital by an ambulance and he required stitches.
Roncaglia's brother Facundo spent last season on loan at Serie A side Genoa where he made 32 league appearances as his team secured a sixth place finish.
But the Argentina international will be shocked when he witnesses his brother's shocking reaction to a yellow card.