Emiliano Boffelli scored 16 points as Argentina put their World Cup campaign back on track with a disciplined and composed 19-10 victory over erratic Samoa on Friday.
Victory keeps the Pumas in the hunt for the quarter-finals following their opening Pool D defeat to England two weeks ago. Samoa face an uphill battle to make the knock-out stages.
An error-strewn display proved Samoa's undoing, with numerous knock-ons halting their progress and momentum.
They did set up a grandstand finish when replacement hooker Sama Malolo burrowed over five minutes from time, before Argentina veteran Nicolas Sanchez ended Samoan hopes with a last-gasp penalty.
Samoa made a poor start and then paid for some hapless kicking and dubious tactical choices as Argentina steadily clocked up the scores in driving rain.
Samoa full-back Duncan Paia'aua was yellow-carded inside the first 35 seconds for taking out Santiago Carreras in the air.
Just before Paia'aua returned, Argentina made Samoa pay, switching play from one wing to the other before Boffelli darted in off his flank to stretch out an arm and score.
Samoa had been the architects of their own downfall, as veteran fly-half Christian Leali'ifano gifted Argentina possession inside the 22 by taking a free-kick from the wrong place.
Boffelli converted his own try and soon added a penalty before Leali'ifano got the Pacific Islanders off the mark with a three-pointer that bounced on the crossbar and over.
A second penalty from Boffelli pushed Argentina's lead to 13-3, while Leali'ifano missed two straightforward looking kicks at goal in what was quickly turning into a personal horror show.
Leali'ifano turned down another penalty opportunity to kick to the corner but Argentina stole the Samoan line-out.
Moments later, on the stroke of half-time, Samoa had a five-metre scrum, but scrum-half Jonathan Taumateine spilled the ball and allowed Argentina to survive and take a 10-point lead into the break.
With the rain abating, Argentina grew in confidence at the start of the second half, pinning Samoa in the corner before giving away a penalty from a double movement by Boffelli as he sought a second try.
Samoa lost UJ Seuteni, knocked out while making a tackle, and another botched line-out invited more pressure.
A clever Pablo Matera grubber kick led to a penalty deep in the Samoa 22 that Argentina kicked to the corner.
Fierce defence kept Argentina out until Boffelli knocked over his third successful penalty.
Boffelli missed a penalty from halfway, but made up for that with some crucial cover under his own posts to prevent Tumua Manu from running onto a grubber to score.
Samoa finally scored a try five minutes from time through Malolo, with D'Angelo Leuila converting.
But replacement Sanchez had the last word. (AFP)