The Argentine Football Association announced on Wednesday that a long-standing ban on away fans attending games in the country's second division is to come to an end.
The drastic measure was introduced in July 2007 after a young supporter was killed following violent clashes between rival supporters.
It has now been ended with immediate effect, although the decision will not become final in the capital Buenos Aires until it has been agreed to by the region's security chief, and by the CoProSede, the body in charge of organising security at sporting events.
The news is of particular relevance to River Plate, with the country's most successful club currently playing in the second tier for the first time in their history.
On Saturday, a reported 15,000 River fans defied the ban to attend their team's game in Mendoza against Inedependiente Rivadavia.