The Jaguares survived a tense finish to defeat the Western Stormers 30-25 in Buenos Aires Saturday and chalk up a fourth consecutive Super Rugby victory.
Success lifted the Argentine outfit two places to sixth in the combined standings, keeping them in contention for a top-eight finish and a play-offs slot.
Despite losing, the South Africans also moved up the table, replacing the ACT Brumbies from Australia in eighth position on points difference.
It was a close call in the end for the home side after they looked set for a comfortable victory when a penalty try seven minutes from time gave them a 30-18 advantage.
The Stormers, who had not looked like scoring a try at Estadio Jose Amalfitani, suddenly clicked and a Justin Phillips break led to a try by fellow substitute Seabelo Senatla.
Damian Willemse, who inherited the goal-kicking duties when Jean-Luc du Plessis was substituted, converted to leave only five points between the teams.
A couple of penalties after the full-time hooter sounded brought the Stormers within a few metres of the Jaguares tryline and a converted try would have given them victory.
But the Cape Town outfit conceded possession at the lineout and the relieved Jaguares booted the ball into the grandstand to end the round 12 match.
It was a scrappy, penalty-riddled affair that included two late yellow cards with JJ Engelbrecht of the Stormers and Pablo Matera of the Jaguares watching the climax from the touchline.
The Jaguares led from the fourth minute when Matera scored and the hosts were 13-9 ahead by half-time with the rest of the points coming from the boots of Domingo Miotti and Du Plessis.
Ramiro Moyano scored a second Argentine try on 51 minutes, but the goal-kicking accuracy of Willemse kept the Stormers in touch.
Recent Super Rugby debutant Miotti contributed 13 points from two conversions and three penalties off five shots at the posts.
Apart from the Senatla try, Du Plessis slotted four penalties and Willemse a conversion and two penalties for the Stormers.
The Jaguares start a four-match Australasia tour next Saturday against the Otago Highlanders in Dunedin while the Stormers have a bye.