They had to wait until just before the hour mark for Bruno Vieira to break the deadlock, then Rafael Sobis added a second in the 75th minute.
And it proved to be a profitable victory as second-placed Atletico collapsed to a 3-0 defeat at Internacional.
Atletico had seemingly got back on track at the weekend with a 6-0 win over Figueirense following four games without a win, but they fell behind in the 67th minute when Jackson opened the scoring for the hosts.
And further goals in the last 10 minutes from Fred and Cassiano Dias Moreira killed them off.
There was also defeat for fourth-placed Vasco da Gama, 2-0 at home to Sau Paulo.
Luis Fabiano (21) and Osvaldo (49) were the goalscorers.
Corinthians came away from a dramatic second half against Flamengo with a 3-2 victory.
Renato Dos Santos scored the only goal of the first half to send Flamengo in ahead at half-time, but Edenilson (62) and Paulo Andre (76) turned it around after the break.
Emerson then extended the lead in the 90th minute, but there was still time for Liedson to cut the gap back to one in the third minute of stoppage time.
A 37th-minute penalty from Walter Montillo and a last-minute effort from Willamis Souza gave Cruzeiro a 2-0 win over Portuguesa.
Roni scored twice to help Figueirense beat Atletico Goianiense 3-1.
Roni netted either side of half-time after Diego Giaretta had cancelled out Aloisio's opener.
Two goals in five minutes from Rildo (74) and Marcinho (78 pen) saw Ponte Preta come from behind to beat Nautico Recife 2-1.
Douglas had opened the scoring in the fifth minute for Nautico, who also had Patric sent off in the last minute.
Quickfire goals from Andre (54) and Ezequiel Miralles (57) gave Santos a 2-0 win at Botafogo.