A first half Jaguares blitz, which saw them take a 22 point lead, set the tone for an eventual 40-27 victory over the Waratahs in Sydney.
The visitors outscored their hosts by five tries to three but the result could easily have gone the other way as the Jaguares were reduced to 13 men at one stage. Leading 25-10 just before the half-time break, Guido Petti and Benjamin Macome were shown yellow cards within a minute of each other.
The Waratahs took advantage of the numerical advantage in the early stages of the second half with two tries to reduce the deficit to a solitary point but the Jaguares bagged two second half tries of their own to grind out the victory.
The Jaguares made a fast start as Nicolás Sánchez slotted a first minute penalty before loose forward Pablo Matera dotted down for the game's opening try in the sixth minute.
The Jaguares carved open the Waratahs' defence as Matera raced away. Sánchez' extras ensured a 10-0 lead.
The visitors continued their dominance in the early stages as Matías Orlando sprinted away to bag his side's second try of the night. Sánchez failed with the extras but the Jaguares held a 15-0 lead after 13 minutes.
Bernard Foley gave the home fans something to smile about when he slotted an 18th minute penalty but Sánchez slotted a three-pointer of his own in the 26th minute as the Jaguares maintained their 15-point lead.
The Waratahs were reduced to 14-men in the 29th minute when Ned Hanigan was shown a yellow card for striking an opponent in the face and the Jaguares took full advatage.
From an attacking line-out, their forwards went to work with a few pick-n-goes that eventually saw Benjamin Macome power over from close range in the 31st minute. Sanchez converted for a 25-3 lead.
However, Israel Folau handed the home side some momentum late in the half when he beat Joaquín Tuculet to a high ball before cutting his way over the try-line. Foley added the extras to see the home side trail 10-25 just before the half-time interval.
The Jaguares ended the half with 13 players on the field after locks Guido Petti and Macome were sent to the sin bin within a minute of each other.
Foley got the second half scoring going in the 42nd minute when cut through the heart of the Jaguares defence to grab his side's second try. He made no mistake with the conversion to trail 17-25. Foley was in the thick of it all again two minutes later when he sniped through for his second try of the match. Another successful conversion saw the Waratahs trail 24-25.
After soaking up the pressure, the Jaguares hit back in the 55th minute when captain Agustin Creevy dotted down after a powerful rolling maul. Sánchez added the conversion to stretch the lead to 32-24.
Foley and Sánchez traded penalties soon after as the Jaguares' lead became 35-27 in the 62nd minute. The Jaguares continued to punish the Waratahs whenever the opportunity presented itself.
Matías Moroni showed plenty of skill and composure in the 68th minute when he chased down his own chip ahead to score his side's fifth try of the match. Sánchez failed with the extras but the lead was stretched to 40-27.
The Waratahs pushed hard for a late comeback but it was not meant to be as the Jaguares bagged their first-ever victory in Australia.
Man of the match: Bernard Foley came into his own in the second half as he benefitted from some straight running while Michael Hooper put in the dirty work to get his team on the front foot. Nicolás Sánchez controlled matters with his boot but as always, captain Agustin Creevy led from the front and put in a monumental effort.
For the Waratahs:
Tries: Folau, Foley 2
Cons: Foley 3
Pens: Foley 2
For the Jaguares:
Tries: Matera, Orlando, Macome, Creevy, Moroni
Cons: Sánchez 3
Pens: Sánchez 3
Yellow cards: Ned Hanigan (Waratahs, 29; foul play - striking an opponent); Guido Petti (Jaguares, 39; collapsing the maul); Benjamin Macome (Jaguares, 40; repeated infringements - not retreating the required 10 metres)
Waratahs: 15 Israel Folau, 14 Bryce Hegarty, 13 Rob Horne, 12 David Horwitz, 11 Cam Clark, 10 Bernard Foley, 9 Jake Gordon, 8 Michael Wells, 7 Michael Hooper (captain), 6 Jack Dempsey, 5 Dean Mumm, 4 Ned Hanigan, 3 Sekope Kepu, 2 Tolu Latu, 1 Tom Robertson.
Replacements: 16 Damien Fitzpatrick, 17 Paddy Ryan, 18 Angus Ta'avao, 19 David McDuling, 20 Ryan McCauley, 21 Matt Lucas, 22 Taqele Naiyaravoro, 23 Andrew Kellaway.
Jaguares: 15 Joaquín Tuculet, 14 Matías Moroni, 13 Matías Orlando, 12 Jerome de la Fuente, 11 Emiliano Boffelli, 10 Nicolás Sánchez, 9 Martín Landajo, 8 Leonardo Senatore, 7 Juan Manuel Leguizamón, 6 Pablo Matera, 5 Benjamin Macome, 4 Guido Petti, 3 Enrique Pieretto, 2 Agustin Creevy (captain), 1 Nahuel Tetaz Chaparro.
Replacements: 16 Julián Montoya, 17 Santiago García Botta, 18 Ramiro Herrera, 19 Ignacio Larrague, 20 Rodrigo Báez, 21 Gonzalo Bertranou, 22 Joaquín Díaz Bonilla, 23 Santiago Cordero.
Referee: Ben O'Keeffe (New Zealand)
Assistant referees: Angus Gardner (Australia), Jordan Way (Australia)
TMO: Ian Smith (Australia)