Barinas, Venezuela, Feb 15: Boca Juniors were held to a 0-0 draw by Venezuelan hosts Zamora on Tuesday in the Argentine power club's opening match in the group stage of this season's Copa Libertadores.
Zamora was playing its first ever game in the continental competition, while Boca Juniors has won the competition on six occasions and is among the favorites this year.
In other games Tuesday, Colombia's Atletico Nacional had a 2-0 home win over Universidad de Chile 2-0, and Uruguay's Defensor Sporting also won 2-0 at home against Deportivo Quito of Ecuador.
In Group 4, Boca Juniors, which won the Argentine Apertura championship going undefeated in 19 games and conceding just six goals, did not create many clear cut chances against Zamora, despite enjoying the majority of possession.
Uruguayan Santiago Silva came closest for Boca Juniors with a header that hit the post and rebounded into the goalkeeper's arms in the 90th minute.
Silva was making his debut for Boca Juniors after signing from Italian team Fiorentina in January. He is only eligible to play in the Copa Libertadores, not the domestic league.
"We couldn*t get the three points we wanted, but a point helps us," Zamora's Jaime Bustamente said after the game.
The Group 4 opener was last week, when Brazil's Fluminese won 1-0 at home against Argentine side Arsenal.
In Medellin, Colombia, Atletico Nacional's Juan Valencia opened the scoring with a left foot volley from inside the penalty area in the 29th in the Group 8 game.
Dorlan Pabon got the second for Atletico Nacional after holding off a defender and shooting low underneath the goalkeeper from inside the box in the 81st.
Universidad de Chile, the current Copa Sudamericana champion, had only one shot all game.
Argentina's Godoy Cruz and Uruguay*s Penarol play on Thursday in this week's other Group 8 match.
At Montevideo in Group 7, Defensor Sporting took the lead against Deportivo Quito through a penalty from Braian Aleman in the 23rd. Maximilian Callorda added the second 12 minutes from the end.
The result moves Defensor Sporting onto three points from two games played, while Deportivo Quito stays on one point after drawing last week at Mexican team Guadalajara. Argentine side Velez Sarsfield is in first place in Group 7, having defeated Defensor Sporting 3-0 last week.
Group games continue on Wednesday and Thursday, with reigning Copa Libertadores champions Santos, of Brazil, playing Peru's The Strongest on Wednesday.