Manu Ginobili of the NBA’s San Antonio Spurs added 12 points and the Brooklyn Nets’ Luis Scola 18 as the more experienced Argentines proved too much for the sloppy African qualifiers.
Argentina is the only country since 1988 to have won an Olympic basketball gold medal other than the USA.
They won in Athens in 2004 on the strength of their “golden generation” of core players including Ginobili, Scola and Andres Nocioni.
But with Ginobili now 39 and the other two 36 years old, time is running out for that decorated cadre to take home another medal.
Cheered on by a boisterous turnout of fans from their nearby homeland, which borders on Brazil, Argentina jumped out to an 11-0 lead.
They never looked back, using tough defence and superior ball movement to set up eight first-half three-pointers and take a 50-31 halftime lead.
More of the same followed in the second half, with the Argentines cruising to the final buzzer. They finished with 15 three-pointers.
Nigeria was led by Ikechukwu Diogu’s 15 points and 13 rebounds, and 14 points from Ebi Ere.