Sergio Aguero's diving header clinched three points for Argentina, who had to survive a late barrage from Uruguay.
Argentina bounced back from their draw with Paraguay to overcome arch-rivals Uruguay 1-0 in a tense encounter at the 2015 Copa America.
Sergio Aguero's second-half header separated the two sides in La Serena, Chile, and gave Argentina victory to take Gerardo Martino's side to four points in Group B after they started the tournament with a 2-2 draw.
After his team surrendered a two-goal lead against Paraguay on Saturday, Martino would have been pleased with how Argentina ground out a result at the Estadio La Portada de La Serena, although the 52-year-old coach had to watch almost an hour from the stands.
Martino was sent off in the 33rd minute, seemingly arguing a yellow card against Uruguay's Nicolas Lodeiro was too lenient.
Although Argentina produced more chances, Uruguay coach Oscar Tabarez should take some positives from his team's performance, as they had a handful of genuine opportunities to score.
Bordeaux striker Diego Rolan was the most profligate of the Uruguayans, missing three top chances, including his blaze over the bar from inside the box with 15 minutes remaining.
The win took Argentina into second position in Group B on four points, only behind Paraguay on goals scored, while Uruguay (3) sit third ahead of Jamaica (0).
After a tight opening to the game, Argentina generally had the better of the first half.
Angel di Maria produced the first genuine chance but shot straight at Uruguay goalkeeper Fernando Muslera.
Aguero forced Muslera into a stop down low with a header in the 26th minute, while Uruguay tested their opponents aerially as well.
Rolan had two good chances to score, failing to get his head on a cross in the first instance, before glancing an effort wide at the half-hour mark, while Diego Godin also had an opportunity from a corner.
But neither side could breach the opposing defence until Aguero's effort after the break.
Javier Pastore found a pocket of space on the right in the 56th minute, releasing Pablo Zabaleta on an overlapping run and the Manchester City full-back whipped his cross to the near post, where a diving Aguero provided the final touch past Muslera.
The rest of the second half descended into a collection of fouls, scuffles and yellow cards as Uruguay became increasingly frustrated, with Rolan's miss after Sergio Romero parried a drive into the forward's path not helping their mental state.
Rolan almost redeemed himself with two minutes left but his header from a corner was cleared off the line, while Romero was forced into a top save to deny Abel Hernandez soon after.comments