First-half goals from Diego Giaretta and Renie saw Campeonato bottom side Atletico Goianiense pull off a shock 2-1 victory at league leaders Fluminense.
The hosts had just lost one league game this season prior to the latest round of fixtures but they were caught cold when Giaretta put Goianiense ahead in the 18th minute.
The visitors went further ahead three minutes before the interval thanks to Renie and although substitute Morais Michael halved the deficit in the 64th minute, Fluminense could find no way back.
As a result, Goianiense went level on points with Palmeiras and just goal difference now separates the sides.
Sao Paulo moved up into the top five courtesy of a 3-1 home victory over Portuguesa.
Osvaldo's sixth-minute opener for Sao Paulo was cancelled out by Bruno Mineiro eight minutes before the interval, but the hosts hit back in the second half, with strikes from Bruno Cortes (57) and Luis Fabiano (78) sealing victory.