Ronaldinho mistake costs Flamengo victory
Elsewhere, former Brazil forward Ronaldinho was substituted and insulted by Flamengo fans after his mistake allowed Internacional to snatch a 3-3 draw after trailing 3-1.
The former AC Milan and Barcelona forward lost possession in midfield and the resulting break led to Jesus Datolo scoring the equaliser for the visitors.
Ronaldinho, who had earlier converted a penalty for Flamengo, was taken off by coach Joel Santana shortly afterwards to a hostile reception from the team's supporters.
It was the latest unhappy episode for Ronaldinho, whose form has been going downhill for some time.
Instead, it was left to journeyman forward Alecsandro to provide the sort of moment which used to be associated with Ronaldinho.
The Vasco striker, with his back to goal, met Fagner's cross first time as he hooked the ball into the top corner of the net to give his side a 1-0 win over Portuguesa.
Corinthians coach Tite said that their attempt to win the South American Libertadores Cup for the first time was taking a heavy toll following their defeat at Atletico Mineiro.
Midfielder Danilinho headed the only goal for the Roosters against opponents whose minds are clearly elsewhere.
The unusual format of the complex Brazilian season means that Corinthians' campaign in the national championship clashes with the decisive stages of the Libertadores, which is at the semi-final stage.
"We are in two competitions and we don't have time to breath," said Tite, whose side beat Vasco da Gama 1-0 on Wednesday in their quarter-final second leg.
"We need time to recover from a difficult game. I needed two days before I could sleep properly again because of the adrenalin and it's the same for the players."
A second-half header by Andre Lima gave Gremio a 1-0 win over Palmeiras in a match which pitted former Brazil coaches Vanderlei Luxemburgo and Luiz Felipe Scolari against each other.