Hogg charges through the Argentina defence
Argentina (10) 21
Tries: Tejeda, Tiesi
Pen: Todeschini (4)
Scotland (9) 15
Pen: Paterson (5)
Scotland fell to defeat in the first of two Tests against Argentina at the Stadio Gigante de Arroyito in Rosario.
Chris Paterson's penalty gave the visitors an early lead before debutant Alvaro Tejeda's try helped Argentina into a 10-9 advantage at half-time.
Two Paterson kicks early in the second half gave the Scots a six-point lead.
But Federico Todeschini struck twice to regain the lead for Argentina before Gonzalo Tiesi ran in the hosts' second try of the night late on.
Scotland started brightly and Ally Hogg's powerful run resulted in Argentina being penalised for a high tackle. Paterson, who equalled Scott Murray's Scottish cap record of 87, comfortably kicked his side into the lead after 11 minutes.
Argentina immediately went on the offensive and were themselves awarded a penalty after Matt Mustchin was penalised for a knock on. Todeschini levelled the scores.
Tejeda put Argentina into the lead after 21 minutes when he powered through the Scottish defence to touch down on his international debut. Todeschini converted.
Paterson soon reduced the arrears with two more penalties which sandwiched an injury scare for Argentina when captain Felipe Contepomi required treatment to recover from a collision.
Scotland then missed an opportunity to go back in front when Paterson's penalty was off target. It was the Edinburgh man's first missed kick in 36 attempts at international level.
But Argentina failed to take advantage of that miss with Todeschini's penalty drifting wide as the home side had to settle for a 10-9 lead at half-time.
Scotland debutant Ben Cairns is tackled by Contepomi
Paterson made up for his earlier miss by kicking Scotland into the lead right at the start of the second half and further extended their advantage with another three points in the 48th minute.
Argentina thought they had levelled when Bernardo Stortoni touched down in the corner but the TMO ruled that Paterson's tackle had taken the full-back into touch before crossing the line.
Scotland were awarded a long range penalty in the 53rd minute but fly half Dan Parks' effort went narrowly wide of the posts.
Todeschini then reduced Scotland's lead with his third penalty of the match.
With seven minutes remaining Scotland were caught offside and Todeschini stepped up to fire Argentina back in front.
And as Scotland chased a winning score, Tiesi capitalised on a loose ball to run in Argentina's second try of the evening, which Todeschini failed to convert.
The two sides meet again next Saturday at the Velez Sarsfield in Buenos Aires.
Argentina: Stortoni, Nunez Piossek, Tiesi, Contepomi, De Vedia, Todeschini, Vergallo, Ayerza, Tejeda, Bonorino, C. Fernandez Lobbe, Lozada, Durand, J. Fernandez Lobbe, Leguizamon.
Replacements: Gambarini, Gomez, Stuart, Campos, Lalanne, Fernandez, Senillosa.
Scotland: Paterson, Danielli, Cairns, Morrison, Evans, Parks, Blair, Jacobsen, Ford, Murray, Mustchin, MacLeod, Strokosch, Beattie, Hogg.
Replacements: Hall, Dickinson, Kellock, Brown, Lawson, Godman, Webster.
Ref: Alan Lewis (Ireland)