Argentine playmaker Dario Conca scored two goals and set up two others on Sunday to help Fluminense beat Sao Paulo 4-1 and move to the top of the standings with two rounds to go in the Brazilian league.
Fluminense moved past Corinthians, which was held to a 1-1 draw with Vitoria in Salvador in a match in which striker Ronaldo was substituted in the first half because of a muscle injury.
Seeking its first league title since 1984, Fluminense has 65 points, one more than Corinthians and five more than Cruzeiro, which will host Vasco later on Sunday.
Conca, touted by many as the league's top player this year, participated in all of Fluminense's goals at the Arena Barueri just outside Sao Paulo.
Fluminense first scored on a header by defender Gum off a corner by Conca in the 34th minute.
Sao Paulo equalized with a goal by Lucas in the 56th, but Conca put his team ahead with a shot from inside the area in the 74th. Former Lyon striker Fred increased Fluminense's lead from a rebound by Conca's long-range shot in the 78th.
Conca scored his second goal with a firm left-footer from outside the box in the 88th, extending Fluminense's unbeaten streak to seven matches.
Sao Paulo, a six-time champion stuck in the middle of the standings this year, finished the match two men down. Defender Xandao was red-carded for a hard foul in the 63rd, and midfielder Richarlyson was sent off in the 70th for complaining about a foul called against him.
Corinthians lost the standings lead in the match against Vitoria, a team struggling to avoid relegation to the second division.
Midfielder Danilo opened the scoring at Barradao stadium after a perfect pass from Ronaldo in the 21st. But Vitoria equalized with a penalty converted by Colombian goalkeeper Julian Viafara in the 44th following a handball by midfielder Ralf.
Ronaldo, who was playing in his seventh consecutive match, was substituted in the 30th with an apparent right thigh injury.
Vitoria striker Junior had a goal disallowed due to a controversial offside call in the 65th, prompting several complaints from players and coaches. Corinthians was coming off a contentious 1-0 win over Cruzeiro that contained a late penalty for Ronaldo.
Also Sunday, Botafogo lost 2-1 to Copa Libertadores champion Internacional at Engenhao stadium in Rio de Janeiro, while Luiz Felipe Scolari's Palmeiras - resting all regular starters ahead of the second leg of the Copa Sudamericana semifinals against Goias on Wednesday - lost 2-0 to Atletico Mineiro in Araraquara.
On Saturday, defending champion Flamengo moved away from relegation with a 2-1 victory over Guarani at the Engenhao. Coach Vanderlei Luxemburgo's team, Brazil's most popular, needs at least a draw in each of the final two matches to remain in the top flight next season.
Also, Gremio defeated Atletico Paranaense 3-1 in Porto Alegre to move to fourth place, in position to secure a berth in next year's Copa Libertadores.
The top three teams will earn a spot in Latin America's most important competition, and the fourth-placed club will qualify unless a Brazilian team wins the Copa Sudamericana to automatically advance to the Copa Libertadores.
Three teams have already secured their return to the top flight next year, Coritiba, Figueirense and 1988 national champion Bahia. Coritiba won the second-division title with a 1-1 draw with Icasa on Saturday.
