Brazil produced a ruthless performance as they survived an early bout of pressure before beating Costa Rica 4-1 with an Adriano hat-trick to qualify for the Copa America quarter-finals.
Paraguay full-back Ernesto Cristaldo salvaged a point with a dipping long-range shot as they held Chile 1-1 in the second half of the Group C double bill in Arequipa.
Brazil, who have brought a second-string side, had struggled to a 1-0 win over Chile in their opening game.
On Sunday, they looked far more like world champions as they demolished the Central Americans, who are taking part in the tournament for the third time as guests.
The game was reminiscent of the last meeting between the pair at the 2002 World Cup when Costa Rica created at least as many chances as Brazil but were outgunned 5-2.
Once again, the Ticos were made to pay dearly for missing chances and getting caught at the back.
"We were careless and the Brazilians took advantage, converting four of their six chances," Costa Rica's Colombian coach Jorge Luis Pinto said.
"And we missed our chances when we were in front of their goal. It's a tough blow."
He got little sympathy from his opposite number Carlos Alberto Parreira.
"They began at a tremendous pace which they couldn't keep up," he said. "They played like that for half an hour. But football is about 90 minutes.
"Our decisiveness is part of Brazilian football," he added.
"In the end it made it easier than we expected."
LONG-RANGE STRIKES
Costa Rica were the better side until Alex picked out Adriano, who scored his first goal one minute before halftime.
It was a crucial blow.
Two quick goals by Juan and Adriano put Brazil 3-0 up early in the second half before the Inter Milan player completed his hat-trick in the 67th minute, slotting the ball under goalkeeper Ricardo Gonzalez.
Luis Marin scored a late consolation for the Pinto's team, their first goal of the tournament.
Brazil, who joined Colombia in the last eight, have a maximum six points in the group, followed by Paraguay with four, Chile with one and Costa Rica with none.
Mexican-based striker Sebastian Gonzalez put Chile ahead in the 72nd minute of the second match, making up for his penalty miss against Brazil.
But Cristaldo hit back seven minutes later with the latest of the Copa's long-range strikes as Paraguay, who are fielding their under-23 team and using the tournament as a warm-up for the Olympics, snatched a point.
The remaining six quarter-final places will be decided in the next three days.
Group A will be settled Monday when hosts Peru meet Colombia in Trujillo, preceded by Bolivia against Venezuela in the same stadium.
On Tuesday, Mexico, Uruguay, Argentina and Ecuador will decide who qualifies from the so-called "Group of Death" in Chiclayo, where Mexico stunned Argentina 1-0 on Saturday.
Argentina coach Marcelo Bielsa had suggested Mexico's tactics were negative after the game but his opposite number Ricardo Lavolpe replied on Sunday: "Let him come and coach here and he can teach me how to do it.
"Sometimes, defence is the best form of attack. There's no doubt about it."
