The former AC Milan and Barcelona player's unhappy return was completed when he received a yellow card and his side squandered a 2-0 lead to lose 4-2.
"Everyone knew this was going to happen but for anyone who is used to the Flamengo supporters, it's not really much noise," he told reporters after Sunday's game.
Ronaldinho left Gremio in 2001 to join Paris Saint-Germain in acrimonious circumstances. He angered fans of the Porto Alegre club still further this year when he chose to join Flamengo instead of Gremio on leaving AC Milan.
He was jeered every time he touched the ball and fans held up banners reading "mercenary."
Although Gremio scored four goals, one of the biggest cheers of the afternoon came when Ronaldinho received a yellow card for dissent.
Deivid and Thiago Neves put Flamengo 2-0 ahead but Gremio hit back with goals by Andre Lima either side of half-time before Dougles and Argentine substitute Ezequiel Miralles completed a home win.
Corinthians went top with a 2-1 win over relegation-threatened Avai, coming from behind despite playing most of the second half with 10 men.
Robson put Avai in front after 12 minutes in torrential rain and Leandro Castan was sent off in the 50th minute for a professional foul.
Despite this, Emerson levelled just after the hour and former Portugal striker Liedson grabbed the winner with a header which just crossed the line.
Corinthians have 58 points from 32 games, level with Vasco da Gama who were held 0-0 at home by Sao Paulo, and lead by virtue of the number of games won.
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