Nacional has claimed a crucial three points with a surprise 2-1 win against Vasco da Gama in the Copa Libertadores on Wednesday.
Nacional scored twice to secure the win, although an undeserved goal by the home side kept the game alive to the final whistle.
The Uruguayan club took the lead in the 30th minute when Vasco defender Dede knocked the ball into his own net from a corner.
Vasco were being exposed in the wide areas and they fell two goals behind just after half-time.
Tabare Viudez looked up and crossed for an unmarked Vicente Sanchez who found the goal with a diving header.
Alecsandro gave Vasco an opportunity to get something from the game when he scored in the 74th minute, but the Rio-based club hardly threatened again.
Nacional Asuncion also lost at home in their opening match of the Copa Libertadores group stage.
The Paraguayan club were defeated 2-1 by Cruz Azul of Mexico, with Javier Orozco scoring both goals for the visitors.
In Chile, Union Espanola looked impressive as they beat Junior from Colombia 2-0.
Union dominated and probably should have won by a bigger margin but in the end goals from Emanuel Herrera and Fernando Cordero were enough.
