A last-minute penalty goal was all that separated Argentina from the NSW Barbarians in La Plata on Saturday.
Argentina snatched a 29-27 victory with the last kick despite being outscored by four tries to three.
Two Sekope Kepu tries at either end of the first half gave the visitors a two-point advantage going into the break.
That lead was extended just six minutes into the second period when wing Peter Betham crossed for NSW's third try.
When full-back Drew Mitchell added another on the 60 minute mark, Michael Cheika's inexperienced NSW side looked like taking a big scalp against a fully-capped Test outfit, before two tries within four minutes from replacement hooker Agustín Creevy put the home side right back in the contest.
With Nicolás Sánchez and Bernard Foley exchanging penalty goals in the closing 10 minutes, the NSW Barbarians led by a single point going into the final seconds but a last-gasp Sánchez penalty right on the siren eventually seales the win for the home side.
Having gained valuable experience from playing against their Rugby Championship opponents, NSW's international contingent today fly back to Australia to join the Wallabies training camp.
The remaining Baa-Baas squad members will get another crack at the opposition when the two sides meet again on Friday August 9 at Estadio Padre Martearena in Salta.
Tries: Agulla, Creevy 2
Pens: Hernández 2, Sanchez 2
For NSW Barbarians:
Tries: Kepu 2, Betham, Mitchell
Cons: McKibbin, Foley
Argentina: 15 Martín Rodríguez, 14 Gonzalo Camacho, 13 Gonzalo Tiesi, 12 Santiago Fernández, 11 Horacio Agulla, 10 Juan Martin Hernández, 9 Martin Landajo, 8 Leonardo Senatore, 7 Pablo Matera, 6 Juan Martin Fernández Lobbe, 5 Mariano Galarza, 4 Manuel Carizza, 3 Juan Figallo, 2 Eusebio Guiñazú, 1 Marcos Ayerza.
NSW Barbarians: 15 Drew Mitchell, 14 Cam Crawford, 13 Usaia O'Sullivan, 12 Rob Horne, 11 Peter Betham, 10 Bernard Foley, 9 Brendan McKibbin, 8 Dave Dennis (c), 7 Pat McCutcheon, 6 Jed Holloway, 5 Mitchell Chapman, 4 Will Skelton, 3 Paddy Ryan, 2 Tolu Latu, 1 Sekope Kepu.
Venue: La Plata Rugby Club
Referee: Francisco Pastrana (UAR)
AR1: Juan Hernán Sylvestre (UAR) AR2: Joaquín Otaño (UAR)
TMO: Javier Mancuso (UAR).