Three players and both coaches were sent off on Sunday in a Brazilian derby which had been preceded by a campaign to promote peace between the rivals' sets of supporters.
Trouble erupted early in the second half of the Juventude-Caxias game in Caxias do Sul when Gilmar Iser, coach of the home team, ran on to the pitch to protest a decision.
Iser was sent off while Caxias coach Argel Fucks was also dismissed after an angry exchange with the fourth official.
The enraged Fucks refused to leave and had to be escorted off the touchline by riot police. The incident also prompted a pushing match and play was held up for six minutes.
Tempers were still on the boil when play re-started and Juventude finished with nine men after Alex Morais and goalkeeper Renan were sent off while Caxias had Mika dismissed for kicking an opponent.
Second half goals by Marcos Denner and Julio Madureira gave Caxias a 2-0 win in the Rio Grande do Sul championship match.
Before the game, the clubs had organised a so-called Fraternity Breakfast involving leaders of supporters groups, police officials and their own presidents in an attempt to promote peace.
In the first leg of a Paulista championship semi-final, Cristian scored the winner three minutes into injury-time to help Corinthians beat Sao Paulo 2-1.
Miranda headed Sao Paulo ahead in the 24th minute and Elias levelled with an individual goal four minutes later.
Corinthians striker Ronaldo missed a second-half chance when he shot at Rogerio Ceni after being put clean through and was also booked. Santos beat Palmeiras 2-1 in the other game.
Flamengo qualified for the final of the Carioca (Rio de Janeiro) championship's second stage with a 1-0 win over Carlos Alberto Parreira's Fluminense, Juan scoring the only goal of the 'Fla-Flu' derby.
The match was notable for a remarkable miss by Flamengo striker Josiel, who shot straight at a defender on the line from six metres with the goalkeeper beaten. Botafogo beat Vasco da Gama 4-1 in the tie.
Atletico Mineiro won their 10th game in a row in all competitions as they beat Rio Branco 2-0 in their Minas Gerais championship semi-final, first leg.
Diego Tardelli and Eder Luis scored for the Roosters in a nine-minute spell in the first half.