Argentina won successive tests against France for the first time since its 2007 Rugby World Cup breakthrough when it took the home series opener 30-19 on Sunday.
The Pumas won the previous test in Paris in 2014.
They led 17-3 after half an hour then lost their composure over the next half hour. An under-strength France team pulled ahead 19-17, and had all of the momentum until prop Jefferson Poirot was sin-binned for a deliberate knockdown. Nicolas Sanchez's penalty kick put the Pumas back in front, they stopped their carelessness, and pulled away, making the result safe with a try from a 50-meter gallop by lock Guido Petti seven minutes from the end.
Argentina made two changes, in the forwards, and resumed where it left off from beating Italy 30-24 in Santa Fe the previous weekend.
It pinched French ball in a tackle, counterattacked from 70 meters out, and 10 phases later center Matias Moroni sent winger Manuel Montero untouched into the left corner.
Soon after, Montero stepped one defender, stiff-armed another, and one-hand passed out of a French crowd to send fullback Joaquin Tuculet streaking to the opposite corner.
The Pumas were playing like the French of old. The French replied with a try of the old Pumas: A 10-meter rolling maul, finished by hooker Remi Bonfils, one of seven starting new caps.
France couldn't choose internationals from the national club semifinals this weekend. But after Clermont and Montpellier lost, their players can be summoned by France to Tucuman again for the second test next weekend, when the Top 14 final will be contested by Toulon and Racing 92.
Argentina's discipline disappeared in the third quarter. Captain Agustin Creevy's petulent kick at a Frenchman on the ground wasn't sanctioned, but Javier Ortega Desio was yellow-carded for a deliberate foul, and a string of kickable penalties allowed Plisson to kick France in front.
Then Poirot was sin-binned and the momentum suddenly changed back to Argentina.
Sanchez, who kicked six of his eight goalkicks, regained the lead for the Pumas, and they finished in style when Petti took a pass from a prop on halfway, and ran past Plisson as he romped to around behind the posts.