Rafael Sobis' goal on the stroke of half time proved the difference as Fluminense edged Palmeiras 1-0 at the Estadio Municipal Paulo Machado de Carvalho, preserving their 100 per cent record in the process.
Fluminense have opened the season with back-to-back wins to sit top of the table on six points.
The Laranjeiras-based outfit are two points clear of defending champions Cruzeiro, Sao Paulo, Internacional and Atletico PR, who are locked on four points after slipping up over the weekend.
And Fluminense's star striker Fred paid tribute to coach Cristovao Borges following the club's recent triumph.
"Our movement is very good," said the Brazil international. "To come here and have this result is a great result.
"The coach deserves merit. He arrived, picked the team and uses his quality to get us to do what he asks."
Cruzeiro and Sao Paulo met in a blockbuster clash on Sunday but were forced to share the spoils after playing out an entertaining 2-2 draw at the Estadio Municipal Joao Havelange.
Former Real Madrid and Arsenal striker Julio Baptista put Cruzeiro ahead five minutes after the break and that appeared enough for maximum points until Antonio Carlos levelled proceedings in the second minute of injury time.
Internacional also missed the chance to make it two wins from two after they surrendered a two-goal lead to draw 2-2 at Botafogo.
A first-half brace from Rafael Moura put the visitors in the box seat before two goals in 11 minutes from Emerson Sheik and Pablo Zeballos salvaged a point for winless Botafogo, who ended the match with 10 men following Lucas' red card.
Two goals in the space of five minutes from Mosquito and Marcelo earned Atletico PR a 2-2 draw with Vitoria.
In other results, Corinthians moved third in the standings courtesy of a 2-0 victory over 10-man Flamengo.
Gremio upstaged rivals Atletico Mineiro 2-1 thanks to first-half goals from Alan Ruiz and Lucas Coelho.
Sport Recife won their first match of the season, accounting for lowly Chapecoense 2-1.
Santos were forced to play out a goalless draw against Coritiba, while Figueirense lost 2-0 at home to Bahia.
Elsewhere, Amaral netted an 82nd-minute goal as Goias defeated Criciuma 1-0.
