Brazil slumped to a fourth defeat in their last five World Cup qualifiers on Tuesday after a first-half goal by Diego Gomez gave Paraguay a 1-0 win in Asuncion.
Five-time world champions Brazil, who scraped a 1-0 home win over Ecuador on Friday, are fifth in South American qualifying for the 2026 World Cup with 10 points, ahead of Venezuela on goal difference.
The top six qualify directly for the World Cup in the United States, Mexico and Canada, with the seventh place offering passage via further rounds of qualifiers.
Manager Dorival Jr, who took over from Tite after Brazil's quarter-final exit at the 2022 World Cup, looked forlorn on the sidelines as his side were comprehensively outplayed and fortunate not to lose by more.
Brazil failed to record a shot on target in the first half and fell behind in the 20th minute when Gomez rifled home from the edge of the box, the ball smacking the post on its way past Alisson into the net.
Brazil had only three shots on target in the match, all via a frustrated Vinicius Jr, who has been unable to have the same impact for his country as he has for club side for Real Madrid.
Brazil will look to get their campaign back on track next month when they travel to face Chile before hosting Peru.