Fullback Emiliano Boffelli has scored 16 points in a man-of-the-match performance, as Argentina got their World Cup campaign back on track with a hardfought 19-10 victory over a committed Samoa.
Boffelli scored an early try and converted four of five kicks from the tee to get the Pumas back to winning ways, after the disappointment of their 27-10 loss to 14-man England in their Pool D opener.
"It's a massive victory for us, very important for this tournament," said Argentina captain Julian Montoya, after first thanking his noisy compatriots in the stands.
"The last game against England, we didn't do what we were supposed to do. Today we did it pretty well... still plenty to improve, but that's exciting too."
Samoa managed just one penalty kick from former Wallabies flyhalf Christian Leali'ifano, until replacement hooker Sama Malolo barged his way over the line for his third try of the tournament five minutes from time.
That set up a frenetic finale, but coming off the bench to win his 99th cap for Argentina, Nicolas Sanchez lashed over a final penalty from just inside the Samoa half to make the game safe.
"Extremely proud of the boys, but I think the better team won today," said Samoa co-captain Chris Vui. "Full credit to Argentina, they were more clinical."
England lead Pool D with nine points from two games, four points ahead of Samoa, who beat Chile 43-10 in their opener, and third-placed Japan, with Argentina in fourth place on four points.
After hot and humid conditions for the first two World Cup matches at Saint Etienne, autumn arrivedwith rain making for greasy conditions and a scrappy arm-wrestle of a contest between two physical teams.
Samoa made a calamitous start in the opening minute, when fullback Duncan Paia'aua was shown a yellow card for taking out an Argentine in the air, presenting the Pumas with a chance for some early points on the board.
Argentina struggled to convert territory into scores against England, but had no problems in the ninth minute, cleverly stretching the undermanned Samoan defence to give Boffelli space to cross the line out wide.
The fullback converted his own try and added a 45-metre penalty in the 24th minute, with Leali'ifano - two days shy of his 36th birthday - finally getting Samoa on the board with a three-pointer of his own four minutes later.
Boffelli chipped over another penalty and the Argentina pack did well to hold out the Samoan eight from two five-metre scrums just before the break to go in at halftime with a 13-3 lead.
Argentina laid siege to the Samoan try-line at the start of the second half and finally came away with some points, when Boffelli kicked his third penalty in the 53rd minute.
Samoa had created little, but almost produced a try of the highest quality on the hour mark, when Alai D'Angelo Leuila poked a lovely grubber in behind the defence for Tumua Manu to chase.
Boffelli beat him to it and the Pumas forwards got back to help him retain possession, with Samoa threatening to steal the ball just under the posts.
