Salvador, June 24: Colombia drew on their reserves to defeat Paraguay 1-0 and make it three wins from three in the Copa America group stage.
Carlos Queiroz's side earned all three points at the Arena Fonte Nova in Salvador, despite the coach making 10 changes to the team that beat Qatar last time out.
Gustavo Cuellar's first-half strike, which went in off the right foot of Paraguay goalkeeper Roberto Fernandez, made the difference.
Colombia had a goal disallowed in the second half as well, when substitute James Rodriguez flicked a clever pass with the outside out of his boot to Luis Diaz, who controlled and lashed a shot past Fernandez from 10 yards. After a long wait, a VAR review showed the ball had brushed Diaz's right arm and the goal was ruled out.
Paraguay, who have two points, now face a nervy wait to find out if they have done enough to progress out of Group B with one of the two best third-placed records.
Colombia, the 2001 Copa champions, already knew they were through to the quarter-finals after following up a 2-0 win over Argentina in their opening match with the 1-0 success against Qatar and Juventus winger Juan Cuadrado was the only player retained in the starting line-up.
Derlis Gonzalez squandered an early close-range chance for Paraguay before Colombia began to impress.
Radamel Falcao almost opened the scoring in spectacular style in the 28th minute when he fashioned an overhead kick that went just off target.
The breakthrough came three minutes later when Santiago Arias moved into the penalty area from the right flank. He fed a short pass to Cuellar who stole between two defenders and from a tight angle drove a shot low inside the near post, when Fernandez should have done better, the ball going in off the goalkeeper's right boot.
James replaced Cuadrado in the second half and thought he had created the second goal as Diaz drove home only to be left deflated by the VAR verdict.
Paraguay looked short of ideas but will advance as one of the two best third-placed teams if Japan and Ecuador draw their final Group C match.
What does it mean? Colombia can be happy with depth
Queiroz should have been satisfied with the look of his fringe players. He wanted to see strength in depth and there were some decent performances, but bank on him reverting to a more familiar line-up come the quarter-finals.
Lionel Scaloni owes Colombia a drink
Argentina will be thankful Colombia gave this game their all, because it cleared a path for Lionel Messi and co to leapfrog Paraguay and take second place in Group B. This could have been a night when La Albiceleste suffered another major tournament nightmare, but Colombian assiduousness coupled with a 2-0 win over Qatar means they are guaranteed a quarter-final berth.
The Paraguay goalkeeper will not want to watch replays of Colombia's goal, because it made him look foolish. Cuellar was always going to shoot after darting into space and Fernandez should have had his near post covered.
Colombia play their quarter-final on Friday (June 28) and can begin to make plans for that as they wait to learn their opponents, the Group C runners-up. Paraguay must play a waiting game. They might be going home but could yet be handed a reprieve.