The Real Madrid attacker posed a constant threat down the left in the Group D clash in Nevada, and scored the opener in the 35th minute as he slotted home Lucas Paqueta's first-time pass to finish off a flowing team move.
Girona winger Savio doubled the advantage for nine-times champions Brazil after pouncing on a rebound inside the box, before Vinicius stuck out a boot to divert a clearance from Omar Alderete into the net for his second goal of the night in first-half stoppage time.
Paraguay pulled a goal back after the break as Alderete netted with a superb long-range effort, but any hopes of a comeback were swiftly ended when Paqueta scored from the penalty spot in the 68th minute.
In Group D's other match on Friday, Colombia cruised to a 3-0 win over Costa Rica to move top and book their spot in the last eight thanks to strikes from Luis Diaz, Davinson Sanchez and Jhon Cordoba.
Colombia started well and took the lead in the 31st minute through Liverpool winger Diaz, who converted from the penalty spot after Costa Rica goalkeeper Patrick Sequeira bundled over Cordoba in the box.
As Costa Rica pressed for an equaliser they left themselves open on the break and Colombia made them pay, with Sanchez heading home from a corner in the 59th minute.
Cordoba rounded out the scoring three minutes later after being played through on goal by James Rodriguez.
Colombia top the group with six points after two matches, with Brazil in second on four.
Costa Rica are third with one point and Paraguay are bottom after two defeats.
The win was Colombia's 10th in a row in all competitions, and maintained an impressive run of 20 wins and five draws since March 2022.
Their last defeat came in a 1-0 loss to Argentina in February that year.
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