Fluminense conceded the Brazilian league lead for the first time in 11 rounds after it was held to a 3-3 draw by defending champion Flamengo on Sunday.
Fluminense now trails Corinthians, which on Saturday defeated last-place Prudente 3-0 in Sao Paulo. Fluminense has 42 points from 23 matches, while Corinthians has 44 points from 22 matches.
Also Sunday, Palmeiras coach Luiz Felipe Scolari was ejected for complaining with the referee in his team's 2-0 loss to Sao Paulo, while Copa Libertadores champion Internacional halted Vasco's 14-match unbeaten streak with a 1-0 victory.
Defender Leandro Eusebio put Fluminense ahead with a header off a corner taken by Argentine midfielder Dario Conca in the eighth minute at the Engenhao stadium in Rio de Janeiro.
Former Fenerbahce striker Deivid equalized with an angled shot into the far corner in the 22nd, and defender Deivid put Flamengo ahead in the 40th, sliding near the far post to tap the ball into the top of the net.
Midfielder Rodriguinho equalized from inside the area in the 64th, but midfielder Renato put Flamengo ahead again two minutes later with a powerful free kick straight into the left upper corner.
Rodriguinho pulled Fluminense even again to close the scoring with a goal from just in front of the net in the 73rd. Rodriguinho was replacing playmaker Deco, who couldn't play because of a muscle injury.
Fluminense comfortably led the competition since the 12th round, but it has won only once in its last six matches.
The result also wasn't good for Flamengo, which is only 15th in the 20-team standings, just outside relegation zone.
Corinthians took over the lead with an easy victory over Prudente at Pacaembu stadium. Striker Iarley opened the scoring in the 21st, playmaker Jorge Henrique added to the lead in the 49th and midfielder Elias closed the scoring in the 83rd, giving Corinthians its second consecutive victory - and 11th in 12 home matches.
The four-time national champion remains without veteran striker Ronaldo, who is still struggling to regain his fitness.
Also Saturday, third-place Cruzeiro had its five-match winning streak halted after a 2-2 draw with fifth-place Botafogo at the Engenhao.
Argentine midfielder Walter Montillo scored both goals for Cruzeiro, which hasn't lost in eight matches. Uruguay striker Sebastian Abreu scored from the penalty spot in the 76th to give Botafogo the draw. Cruzeiro players heavily complained about the penalty decision and of a goal called off in the first half.
Internacional entered the title hunt for good with the win over Vasco at the Beira-Rio stadium in Porto Alegre, moving to fourth place and within six points of the lead with a game in hand.
Vasco hadn't lost since 4-0 loss to Santos on June 6.
Vasco coach Paulo Cesar Gusmao hadn't lost in 21 matches. He had kept Ceara unbeaten for seven matches before switching to Vasco in the middle of the competition.
Without young striker Neymar, Santos was held to a scoreless draw with Guarani at Brinco de Ouro da Princesa stadium in Campinas.
Neymar was suspended by the team on Saturday for cursing at his teammates and at coach Dorival Junior after not being allowed to take a penalty kick in the team's previous match. Club directors on Monday will decide whether Neymar will return to the squad for the team's match against Corinthians on Wednesday.
Scolari's Palmeiras lost to Sao Paulo at Pacaembu after allowing second-half goals to midfielder Lucas and striker Fernandao. Scolari was ejected in the 25th after the linesman caught him offending the referee. He had already been ejected in a previous league match for complaining too much.
Six-time champion Sao Paulo is eighth in the standings, while Palmeiras is only 13th.
Vanderlei Luxemburgo's Atletico Mineiro continued to struggle, losing 3-2 to Vitoria at home to remain in relegation zone with only 21 points, four off last place.
Gremio routed Avai 3-0 in Florianopolis, while Atletico Paranaense beat Atletico Goianiense 2-1 in Goiania on Saturday.
