Lionel Messi could not help Argentina extend its unbeaten streak since its World Cup title.
Uruguay beat Argentina 2-0 at La Bombonera Stadium in Buenos Aires on Thursday in a World Cup qualifying match, its biggest victory so far under new coach Marcelo Bielsa. Argentina hadn't lost a competitive match since its group-stage opener against Saudi Arabia during last year's World Cup in Qatar.
Brazil continued its so far poor campaign in qualifying with a 2-1 loss at Colombia, its second consecutive defeat in the round-robin competition.
Striker Luiz Diaz scored twice on headers to lead an impressive turnaround at the Metropolitano Stadium in Barranquilla, with his father celebrating in the stands only days after being released by kidnappers.
Argentina still leads the 10-team South American qualifying group with 12 points from five matches. Uruguay is second with 10 points. Colombia has nine and Venezuela eight. Brazil will host the World Cup champions at the Maracana Stadium in Rio de Janeiro in fifth position, with seven points.
Ecuador, Paraguay and Chile have five points each. Bolivia has three and Peru one.
The 2026 World Cup in the United States, Mexico and Canada will include 48 teams, meaning direct entry for the top six teams from South America. The seventh-place team can earn a berth in an intercontinental playoff.
URUGUAY 2, ARGENTINA 0 Uruguay was aggressive from the start against the World Cup champions. Darwin Núnez nearly opened the scoring with a crossed shot in the 10th minute after a mistake by defender Nicolás Otamendi.
For the first time since Argentina's World Cup title, coach Lionel Scaloni looked jittery as his midfielders struggled to block Uruguay's wingers. His players didn't heed the call and their punishment came in the 42nd minute, when Matias Viña easily stole the ball from Nahuel Molina and gently made a low cross into the penalty box. Ronald Araújo smashed it into the back of the net.
Argentina came close to levelling the scoring on a free kick by Messi and a close-range shot by Otamendi, which forced goalkeeper Sergio Rochet to make a key save near the end of the first half.
After the break, Uruguay kept the pressure on Argentina, which once again counted on Messi and substitute Angel di Maria to find its best chances. Messi hit the bar with a free kick in the 57th minute.
Núnez scored in the 87th minute on a counter after the Uruguayan defence stopped Messi at the edge of its box.
"We never felt comfortable in this match," Messi said.
"Uruguay is a physical team, they have good teamwork. It is always like that against them." Messi's close friend Luis Suárez, who just returned to the Uruguayan national team, did not play.
In the previous round of World Cup qualifying, Uruguay beat Brazil by the same score in Montevideo. Its next match will be against Bolivia.
COLOMBIA 2, BRAZIL 1 With Neymar and Casemiro out with injuries, Brazil coach Fernando Diniz had some major restructuring to do ahead of what he called "a physical encounter" at Colombia. Gabriel Martinelli and midfielder André were picked as substitutes.
Martinelli opened the scoring in the fourth minute after a quick exchange of passes with Vinicius Júnior. Brazil's momentum stalled after the Real Madrid winger left in the 25th minute with a left thigh injury.
Colombia's game up front depended almost exclusively on Diaz. The striker nearly scored after dribbling past several Brazilians in the 30th minute and was stopped by goalkeeper Alisson on two more dangerous shots in the second half.
Diaz equalized with an easy header in the 75th minute; he didn't even need to jump. He added a second goal four minutes later. His father, Luis Manuel Diaz, fell on top of some people next to him in the stands as his son celebrated.
"He is a friend, he suffered a lot these days. This is beyond soccer," Alisson said. "But we are leaving here in disappointment." OTHER MATCHES Bolivia won its first match of this round-robin, beating Peru 2-0 on Thursday. Henry Vaca scored in the 20th minute and Ramiro Vaca in the 86th. The game in La Paz marked the farewell on home soil for veteran striker Marcelo Martins. The 36-year-old is Bolivia's top all-time scorer with 31 goals.
Venezuela and Ecuador played to a 0-0 draw on Thursday, as did Chile and Paraguay.