At the other end of the table, South American champions Santos dropped into the relegation zone after a 3-2 defeat by Coritiba, in which they had two players dismissed and Brazil duo Neymar and Paulo Henrique Ganso booed off by home fans.
Corinthians, who had won only one of their previous five matches squandering a seven-point lead, took the field at Ipatinga under pressure and went behind to first half goals from midfielder Dudu Cearense and striker Guilherme.
However, the second half took on a different complexion with striker Emerson coming on for Corinthians in place of right-back Alessandro.
Emerson pulled a goal back within four minutes when he headed home a corner and four minutes later, was brought down by defender Rever, who was sent off, with Alex equalising from the penalty spot.
Emerson, who won the championship with Fluminense last year and Flamengo in 2009, also laid on the 74th-minute winner for striker Liedson.
Corinthians could have had a fourth goal but goalkeeper Renan saved a late penalty by Alex in added-time.
"Sometimes we go on and don't get it right and people criticise a bit, but what's important is I'm aware of my importance. It's important to make the most of the chance the trainer gives you," Emerson told reporters.
Corinthians have 37 points from 17 matches, three more than unbeaten Flamengo, who meet Atletico Goianiense on Thursday. Vasco da Gama are third with 33 after a 2-0 away win over Avai.
Santos, who won South America's elite Copa Libertadores club championship in June, are 17th on 15 points from as many matches.
Striker Borges twice put Santos ahead but he missed a 70th-minute penalty after Coritiba had equalised for the second time and midfielder Leo Gago scored the winner for the visitors two minutes from time.
Santos had defender Para sent off for a second booking in the 75th minute and captain Edu Dracena was also shown the red card in added-time for dissent.
"We must get back to playing, to being the Santos that enchanted [South] America. We're trying everything, I gave the maximum in the match. It's a phase, we're going to turn things round," a dejected Neymar said.
