Brazilian champions Sao Paulo began their title defence with an unexpected 1-0 defeat to Fluminense at the Maracana stadium on Sunday, Goal.com reported.
Fluminese, who struggled a great deal last season, dominated their opponents for much of the match and claimed the three points courtesy of a long-range strike from Mauricio two minutes into the first half.
Recently crowned Paulista State champions Corinthians were beaten 1-0 by Internacional at the Pacaembu stadium. Former Lyon striker Nilmar scored the only goal of the match in the 9th minute, when he beat a number of defenders before firing the ball home.
Corinthians, who counted with the services of Ronaldo for the match, peppered the Inter goal in the final ten minutes, but they couldn't manage to find an equaliser and slumped to their first home defeat in 27 matches.
At the Olimpico stadium in Porto Alegre, Gremio could only afford a disappointing 1-1 draw with Santos. Gremio went ahead late in the game through Rever, but Colombian midfielder Maurico Molina snatched the visitors a point with a spectacular free-kick five minutes from full-time.
Cruzeiro, who last week beat Universidad de Chile 2-1 in the round of 16 phase of the Copa Libertadores, continued their good run of results with a comfortable 2-0 victory over Flamengo.
The Belo Horizonte giants played with ten men for almost eighty minutes, but proved their superiority with goals from Kleber and Ramires.
Vitoria picked up a comfortable 2-0 victory over Atletico Paranaense in Curitiba, while newcomers Santo Andre fought out a tight 1-1 draw with Botafogo.
But Sunday's most exciting match was the 3-3 draw between Goias and Nautico, two teams who have never won the championship and are expected to struggle this season.
On Saturday,four-time winners Palmeiras came from behind to edge Coritiba 2-1 at the Parque Antartica with a last-gasp strike from Keirrison.
Vanderlei Luxemburgo rested a number of his key players ahead of the Copa Libertadores clash with Sport Recife next week, but his side still proved too strong for the visitors.
Finally, Avai and Atletico Mineiro drew 2-2 and the encounter between Sport Recife and Barueri ended 1-1.
Campeonato Brasileiro: Round One Results
May 9 (Saturday)
Avai 2 - 2 Atletico Mineiro
Palmeiras 2 - 1 Coritiba
Sport Recife 1 - 1 Barueri
May 10 (Sunday)
Atletico Paranaense 0 - 2 Vitoria
Corinthians 0 - 1 Internacional
Cruzeiro 2 - 0 Flamengo
Fluminense 1 - 0 Sao Paulo
Goias 3 - 3 Nautico
Gremio 1 - 1 Santos
Santo Andre 1 - 1 Botafogo