The 1977 Copa Libertadores was the 18th edition of CONMEBOL's top club tournament. The tournament was won by Boca Juniors after defeating defending champions Cruzeiro for their first Copa Libertadores title in a third decisive game. In the two-game finals, both finalists won one game each. A third match therefore had to be played, which remained goalless and Boca Juniors won 5âÂÂ4 on penalties.
The champions and runners-up of each football association were drawn into the same group along with another football association's participating teams. Three clubs from Brazil competed as Cruzeiro was champion of the 1976 Copa Libertadores. They entered the tournament in the Semifinals.
The top finishers of each group in the first phase, plus the defending champions, are placed into two groups of three. The top finisher from each group play in the finals.
The winner is determined by points (i.e., whoever wins the most of two games); goal difference or aggregate score is not used. If the points are tied after two games, a single-game playoff at a neutral sight will be played. If the game is tied after regulation, a penalty shootout will determine the winner.