Substitute Nicolas Lodeiro scored in the second half Thursday to give Uruguay a 2-1 victory over the United Arab Emirates in their first Olympic group match.
Playing in front of a near capacity crowd at Old Trafford, the UAE was the better side for much of the first half against a South American team seen as a medal contender.
The UAE took the lead in the 23rd minute when captain Ismaeil Matar rounded the keeper after latching onto a through ball. The striker should have headed in a second a couple of minutes later, but missed the target.
Uruguay got back in the game after striker Luis Suarez was brought down a few yards from the edge of the penalty area with four minutes to go in the half. Gaston Ramirez took the free kick and curled the ball into the top right-hand corner of the net.
Liverpool player Suarez was booed by the crowd at Old Trafford, where he is reviled for allegedly racially abusing Manchester United defender Patrice Evra last season and then apparently refusing to shake the Frenchman's hand after serving out an eight-match ban.
Uruguay coach Oscar Tabarez brought on Lodeiro for the second half, and it took just 10 minutes for his decision to pay off. The Ajax midfielder ended a fluid move down the left flank by beating UAE keeper Ali Khaseif with a powerful shot from the left of the box.
Uruguay's main national team finished fourth in the 2010 World Cup and won the Copa America title in Argentina in 2011.
"The team still needs to work on fitness. With the entrance of Lodeiro in the second half, we gained control and possession but we still have work to do," said coach Oscar Tabarez, who also heads the country's full-strength team.
The UAE now will likely need to beat host Britain to advance to the knockout round.
"It was a high-level game," Matar said. "If you get a chance, you have to finish that chance."