Former France international David Trezeguet scored both of River Plate's goals as the famous Argentinian outfit claimed promotion back to the country's top division.
River were surprisingly relegated last season and this demise caused uproar amongst fans.
However, supporters yesterday were jubilant as first a dipping volley, then a close-range finish from the 34-year-old ensured victory over Almirante Brown, meaning they took top spot in Prim B Nacional.
"This is unforgettable. In less than a year we put River back where they belong," said coach Matias Almeyda.
Trezeguet, who played a key role in the club's return to the top flight, admitted recently that he has rekindled his love for football in Argentina's second division.