Daniel Muñoz scored the only goal as Colombia edged Congo 1-0 on Tuesday night to secure a place in the World Cup knockout stage.
Muñoz struck in the 76th minute after Colombia had repeatedly been denied by an inspired performance from Congo goalkeeper Lionel Mpasi, who produced five difficult saves inside the first 20 minutes.
Mpasi had no chance to stop Muñoz’s left-footed effort from inside the box after it deflected off a defender. It was Muñoz’s second goal of the tournament, and the Crystal Palace defender was named man of the match.
"We played with intensity and aggression, and we stuck to our style," Muñoz said. "We earned these three points as a team and for all the fans who came out to support us. This victory gives us a morale boost. We don't want to settle for this."
Congo came close to equalising twice in stoppage time, but Colombia goalkeeper Camilo Vargas produced a superb save to deny a long-range effort from Nathanael Mbuku before also stopping a header from Chancel Mbemba off the resulting corner.
"We probably could have scored more goals, but Congo made it difficult and it was tense there until the end," Colombia coach Néstor Lorenzo said. "But I think we were the deserved winners."
Colombia forward Luis Díaz had two goals disallowed late in the second half, one for a foul in the 79th minute and another for offside in the 80th minute.
Congo had opened its first World Cup in 52 years with a surprise 1-1 draw against Cristiano Ronaldo’s Portugal.
Colombia now has six points from two matches in Group K, sitting two points ahead of Portugal and five ahead of Congo. Portugal defeated Uzbekistan 5-0 in Houston earlier on Tuesday, with Ronaldo scoring twice.
Colombia will need at least a draw against Portugal on Saturday to win the group, which would also be enough for Portugal to advance to the knockout stage.
Colombia, ranked 11th in the world and third among South American teams behind Brazil and Argentina, began the tournament with a 3-1 win over Uzbekistan. Congo, ranked 47th, has faced preparation challenges due to an Ebola outbreak, with many fans unable to travel because of quarantine restrictions.
One supporter who managed to attend in Guadalajara was Michel Nkuka Mboladinga, known for posing as a statue of assassinated Congolese independence hero Patrice Lumumba during the Africa Cup of Nations. He maintained his statue-like pose throughout the match.
Colombia had never previously played out a goalless draw in 23 World Cup appearances.
The team improved after Juan Quintero came on as a substitute for James Rodríguez, who joined Colombia greats Freddy Rincón and Carlos Valderrama with 10 World Cup appearances.
Colombia dominated early, creating several chances that Mpasi kept out, including long-range efforts from Rodríguez, Johan Mojica and Gustavo Puerta, as well as close-range attempts from Díaz and Muñoz. Mpasi also made a key save from Díaz in the 50th minute.
"Our goalkeeper was excellent today, but I'm not surprised. He's been having excellent matches with us," Congo coach Sébastien Desabre said. "Collectively the defense had a hard time but we did defend well overall, except for the goal. We must recognize that Colombia is superior, even though we could have equalized in the end. Now we have a decisive match ahead of us."