Italy: (9) 16
Tries: Stanojevic
Cons: Bortolussi
Pens: Bortolussi (3)
Argentina: (3) 23
Tries: Avramovic, Todeschini
Cons: Todeschini (2)
Pens: Todeschini (3)
Fly-half Federico Todeschini scored 18 points as Argentina followed up last week's win over England by beating Italy in Rome.
The visitors trailed 9-3 at half-time but edged in front after the break when Todeschini crossed for a try.
Miguel Avramovic scored the Pumas' other try and a Marko Stanojevic effort could not save Italy, with Todeschini sealing victory with a late penalty.
The win was Argentina's sixth in a row against Northern Hemisphere teams.
Italy coach Pierre Berbizier said: "I think they are strong outsiders for the World Cup and they will be dangerous opponents for any team.
"They climbed up to sixth in the world rankings after beating England and they deserve to be up there.
"We didn't play the way we had hoped, while Argentina played with intelligence.
"When we had them under some pressure, they stayed calm and they have players who were able to get them out of danger."
Italy: Bortolussi, Canavosio, Canale, M. Bergamasco, Stanojevic, Pez, Griffen, Lo Cicero, Festuccia, Castrogiovanni, Dellape, Bortolami, Zanni, M. Bergamasco, Parisse.
Replacements: Ongaro, Nieto, Del Fava, Sole, Picone, Scanavacca, Pozzebon.
Argentina: Martin Hernandez, Corleto, Avramovic, M. Contepomi, Agulla, Todeschini, Fernandez Miranda, Ivan Ayerza, Ledesma, Scelzo, Lozada, Albacete, Durand, J. Fernandez Lobbe, Longo-Elia.
Replacements: Basualdo, Francisco Gomez, J. Arocena, J. Arocena, Leguizamon, Vergallo, Senillosa, Gomez Cora.
Referee: Craig Joubert (South Africa)