Fernando Belluschi scored just before the half-hour mark on Thursday, meaning the 2014 champions will need only a draw in the return match on August 10 to qualify for the last eight, reports Xinhua news agency.
Brazil's Botafogo also secured a 1-0 away victory in their round of 16 first leg against Nacional of Uruguay after a first-half strike from Joao Paulo in Montevideo.
Earlier, Diego Bejarano scored in second-half stoppage time to earn Bolivia's The Strongest a 1-1 home draw with Lanus of Argentina. Nicolas Pasquini had given the visitors the lead just before halftime.
The Copa Libertadores is South America's top club competition, featuring teams from the 10 member nations of the South American Football Confederation (CONMEBOL).
The winners 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.