Paraguayan side Nacional saw off Zamora of Venezuela 1-0 in their Copa Libertadores Group Four clash in Asuncion on Thursday.
The goal for the home side came in the 10th minute when Marcos Melgarejo was on hand to score after Zamora goalkeeper Yanes Angulo had blocked an earlier effort.
Nacional came close to doubling their advantage from Marcos Riveros' beautifully-executed free-kick, but goalkeeper Angulo saved.
Nacional coach Gustavo Morinigo said: "We did not play well, but today the first thing was to win. We obtained the points and that it is the beginning. We lacked many things and in this class of opposition it can cost us. We have to correct a lot, especially in possession of the ball and in attack."
Zamora's Angulo added: "It was the kind of match where the team which made fewer mistakes was going to win, and we go away empty-handed.
"I am sad as I believe that we deserved a bit more. Now, we can only look ahead to the next game, to clinch three points at home (against Santa Fe next month)."
Nacional's victory took them to three points, level with Copa holders Atletico Mineiro of Brazil and Colombian side Santa Fe, but having played a game more than either of those sides. Zamora are still looking for their first points after two games.
The Strongest prevail
In Group One, Bolivian giants The Strongest defeated Peruvian champions Universitario 1-0 in La Paz.
The visitors created two early openings, with Carlos Olascuaga rattling the post after going one on one with Strongest goalkeeper Gustavo Fernandez after 15 minutes before Luis Garcia Uribe did likewise with a header.
At the other end, Boris Alfaro's chip was cleared off the line by defender Nestor Duarte, but the breakthrough finally came after 70 minutes when Diego Wayar's effort from outside the box proved too good for Universitario goalkeeper Jose Carvallo.
"It is a dream night," said Wayar. "I was waiting for this opportunity for so long and I am grateful to all my team-mates. To score a goal on my debut in an international tournament is something that I have been dreaming about for so long, I am really happy."
The result drew The Strongest level with Argentina's Velez Sarsfield and Brazilian side Atletico Paranaense at the top of the group, but having played an extra game, while Universitario sit pointless at the bottom.