SALVADOR (REUTERS) - Colombia enjoyed a 1-0 win over Paraguay despite fielding a second-string side to make it a clean sweep of victories in their Copa America group stage campaign, leaving Paraguay's hopes of staying in the tournament hanging by a thread.

Colombia were guaranteed a place in the last eight as Group B winners and made 10 changes from the side that beat Qatar in their last outing but still dominated play while Paraguay, who had to win to ensure they progressed, barely caused any danger.

Midfielder Gustavo Cuellar put Colombia ahead just after the half-hour mark, sliding the ball through the legs of Paraguay goalkeeper Roberto Fernandez, while Luis Diaz struck in the second half but the goal was ruled out by VAR.

The technology was used again in stoppage time to over-rule a penalty that had been awarded to Colombia.

Carlos Quieroz's Colombia side finished top of the group with nine points, while Argentina came second with four and also progressed to the quarter-finals after beating Qatar 2-0.

Paraguay are third on two, with Qatar last with one.

Paraguay must hope Monday's game between Japan and Ecuador ends in a draw as victory for either side would send them out.