Estudiantes' game with title challengers Lanus was abandoned at half-time after news of the death reached officials at the Ciudad de La Plata stadium in the capital of Buenos Aires province.
"The police reported a (Lanus) supporter had died and in the face of this situation it was necessary to suspend the match," Estudiantes president Enrique Lombardi said.
"It was a unanimous decision by both clubs... It was for humanitarian reasons."
It was the second match abandoned in three days after Saturday's game at Velez Sarsfield was marred by trouble from fans of visiting side All Boys.
Local media reported the fighting between Lanus supporters and police had started before the match kicked off and another fan was in serious condition.
Estudiantes were 2-0 up at half-time against Lanus, who are third in the "Final" championship standings with 29 points from 16 matches, three points behind joint leaders Newell's Old Boys, who were at home to Union in a later match, and River Plate.
"This violence doesn't come from football, it's a social problem," Estudiantes coach Mauricio Pellegrino said.
"Football reflects the violence in society," added Pellegrino, who returned home to Argentina to take charge of Estudiantes in April after 15 years in Spain and England as a player and coach.