Nacho Scocco opened the scoring for the visitors with a free-kick and Marcelo Larrondo put the result beyond doubt with a late header at the Defensores del Chaco stadium on Tuesday.
The return leg will be played at River Plate's Monumental stadium in Buenos Aires on August 8.
The Copa Libertadores is South America's top club competition, featuring teams from the South American Football Confederation's (CONMEBOL) 10 member nations.
The winner will qualify for the FIFA Club World Cup in the United Arab Emirates in December.
(This story has not been edited by Social News XYZ staff and is auto-generated from a syndicated feed.)
About VDC
Doraiah Chowdary Vundavally is a Software engineer at VTech . He is the news editor of SocialNews.XYZ and Freelance writer-contributes Telugu and English Columns on Films, Politics, and Gossips. He is the primary contributor for South Cinema Section of SocialNews.XYZ. His mission is to help to develop SocialNews.XYZ into a News website that has no bias or judgement towards any.