Juan Roman Riquelme converted a first-half penalty as 10-man Boca Juniors moved into second place in their Copa Libertadores group with 1-0 away victory over Nacional.
The 44th-minute goal at Montevideo's Centenario Stadium was Riquelme's first since his return to the Argentine club following a seven-month exile from football.
The visitors were reduced to 10 men midway through the first half when Claudia Perez was shown a second yellow card for bringing down Juan Albin in the area.
Veteran striker Ivan Alonso squandered a chance to give his side the lead by firing his spot-kick over the crossbar.
Riquelme made the home side pay when he coolly slotted into the top left corner after Andres Scotti's rash challenge on Juan Manuel Martinez.
Former Villarreal star Riquelme has now scored 24 Copa Libetadores goals, surpassing Boca legend Martin Palermo's mark of 23.
The result lifts Boca into second place in Group 1, one point behind Nacional.
In other matches on Thursday, Arsenal de Sarandi beat Sao Paulo 2-1 and San Jose defeated Millonarios 2-0.