Muricy Ramalho quit as Fluminense coach after Sunday's 0-0 draw with Flamengo in the Rio Cup.
Ramalho, whose clubs won four of the last five Brazilian league titles, said he had already made his decision before the match, but did not want to leave his players without command against the team's biggest rival.
Ramalho said in a statement he resigned because directors were not able to improve the club's conditions as promised when they hired him in the beginning of 2010. He had been complaining that the team lacked an adequate training center and had always wanted other off-the-field improvements needed for a top club in Brazil.
Local media reported that Ramalho was in disagreement with some of the club's directors.
Ramalho turned down an offer to coach the Brazilian national team after the team's elimination in the 2010 World Cup, saying he would honor his contract with Fluminense.
The 55-year-old coach led Fluminense to the Brazilian league title last year, the team's first in nearly three decades. He won 28 matches, drew 15 and lost 11 ahead of the traditional Rio club.
The announcement came after a lackluster 0-0 draw at the Engenhao, where neither Flamengo's Ronaldinho or Fluminense's Argentine playmaker Dario Conca were able to add spark to their teams.
The Rio Cup is the first stage of the Rio de Janeiro state championship. Led by recently-signed Ronaldinho, Flamengo won the first stage, the Guanabara Cup, automatically securing a spot in the state final against the Rio Cup winner.
Vasco defeated Madureira 4-2 in Volta Redonda behind three goals by midfielder Bernardo, and on Saturday Botafogo routed Americano 4-0 at Engenhao stadium behind two goals by Argentine striker German Herrera and one by Uruguay forward Sebastian ''Loco'' Abreu.
In the Sao Paulo state tournament, there were no changes atop the standings as Sao Paulo, Corinthians, Santos and Palmeiras won their weekend matches. The teams are tied with 28 points each after 13 rounds, but Sao Paulo has the tiebreaker advantage because it has more victories.
It routed Santo Andre 3-0 on Sunday at Morumbi stadium behind goals by striker Dagoberto, young playmaker Lucas and midfielder Casemiro.
Corinthians allowed a 90th minute equalizer at Mirassol but substitute midfielder Bruno Cesar scored again in injury time for a 3-2 victory.
On Saturday, young playmaker Paulo Henrique Ganso scored a goal and set up another in his first match after nearly seven months out of action because of knee surgery, helping Santos beat Botafogo 2-1 at Vila Belmiro stadium. Brazil midfielder Elano scored the other goal for Santos.
Also Saturday, Luiz Felipe Scolari's Palmeiras defeated Sao Bernardo 2-0 at Caninde stadium in Sao Paulo, while fifth place Ponte Preta was held to a 1-1 draw with last place Prudente in Campinas.
The top eight clubs will qualify for the competition's quarterfinals.
