Paraguayan side Libertad all but secured their place in the knockout stages of the Copa Libertadores on Tuesday with a 1-0 win over San Martin.
San Martin defender Julio Cesar Moreyra was sent off for an intentional hand ball after 23 minutes and Libertad midfielder Sergio Aquino stepped up to convert the resulting penalty.
The Peruvian champions squandered their best chance to equalise when striker Heber Arriola had a penalty of his own saved by Libertad goalkeeper Tobias Vargas.
Libertad are unbeaten from their four matches and top Group One with 10 points, while San Martin are second with six.
In Group One’s other match on Tuesday, Mexican outfit San Luis played out a 1-1 draw with Colombia’s Once Caldas.
Once Caldas have drawn three of their four games to sit third in the group with three points while San Luis are bottom with two.
In Group Three, three-time champions Nacional recorded a surprise 1-0 away victory over Argentinos Juniors.
Nacional striker Santiago Garcia scored the only goal of the game in the 34th minute to silence the fans at the Diego Armando Maradona Stadium in Buenos Aires.
Despite the loss, Argentinos still top the group with seven points from four games, while Mexican side America are one point behind but have game in hand.
Nacional are third on four points while Brazilian side Fluminense are bottom of the pool with two.