Boca Juniors were crowned champions of Argentina for a 32nd time after rivals Banfield suffered defeat on Tuesday.
A 1-0 loss to San Lorenzo left Banfield unable to catch Boca, who are five points clear at the top.
Guillermo Barros Schelotto’s men have lost just three league games this season, with Boca’s title moving them a step closer to River Plate’s record of 36.
Boca have been led by Dario Benedetto (18 league goals, three assists) and 21-year-old Argentinian Cristian Pavon (nine goals, seven assists).
Fernando Belluschi scored a 56th-minute winner for San Lorenzo in their victory over Banfield.
Boca (59 points) have two games to play, as do third-placed River (52), while Banfield (54) and San Lorenzo (52) have one each.
Schelotto, who won Argentine, South American and world club titles as a player with Boca, also played four successful seasons with Colombus Crew in the MLS and has been linked with the new job at expansion side LAFC.
His Boca Juniors were the outstanding side in the country this year, scoring more goals than any other club in the 30-team league and conceding less than all but one.