Former Barcelona and FIFA Player of the Year Ronaldinho helped lead Flamengo to a 1-0 victory at Coritiba a day earlier, crossing for substitute Jeal's headed winner in the 89th minute at the Engenhao.
Unbeaten Flamengo have 33 points from 15 matches after a fourth consecutive win, one ahead of Corinthians, who have taken only four points from their last four matches but still have a game in hand over the new leaders.
"It's everything we dreamed of. We know there's still a long way to go but to feel this taste [of the lead] is very good," Ronaldinho told reporters.
Corinthians, who had won nine of their opening 10 matches before the loss of form, went behind at the Arena da Baixada in Curitiba from a penalty by midfielder Cleber Santana in the 36th minute after Madson was brought down by Weldinho.
The visitors equalised three minutes after half-time when midfielder Paulinho was fouled in the box and Alex converted the penalty, but 19th placed Paranaense held on for the draw.
Coach Dorival Junior was sacked by 13th-placed Atletico Mineiro after a 2-1 defeat by Figueirense on Saturday in the 24th coaching change of the year among the 20 first division teams.
Champions Fluminense lost 3-0 to bottom-placed America-MG at the Alligators' Arena in Sete Lagoas in their second match without Brazil striker Fred, who asked to be dropped during the week for psychological reasons.
Fred, who missed Thursday's 2-0 win over Internacional, was chased by angry fans after leaving a Rio bar in the early hours of Wednesday and threatened to quit the club.
South American champions Santos ended a run of three defeats with a 1-0 win over Ceara to climb out of the relegation zone. Santos have three games in hand.
