The first round of the Copa Libertadores drew 32 teams into eight groups of four; two of these teams came from the preliminary round. In each group, teams played against each other home-and-away. The top two in each group advanced to the second round.
The first leg match between Olimpia and Cobreloa played in Calama was suspended at the end of the first half due to crowd interference; an object was thrown at the referee and sustained an injury. At half-time the result was 1–1, but CONMEBOL awarded Olimpia a 2–0 victory and closed Cobreloa's stadium for a period of time.