Brazil Serie A wrap: Fluminense clinch title
Former Olympique Lyonnais striker Fred scored in the 88th minute to hand his side the win as they secured the title with three rounds to spare.
Fred had given Fluminense the lead in first-half stoppage time before Mauricio Ramos put the ball in his own net to double the away side's advantage.
But Palmeiras, who are in deep relegation trouble, fought back through Hernan Barcos in the 62nd minute before Patrick Vieira drew his side level three minutes later.
Fluminense looked like being forced to wait another week to celebrate before Fred tapped home the rebound from a Wellington Nem shot with injury time looming to deliver the Rio de Janeiro side's fourth Brazil Serie A title in their history.
Second-placed Gremio, who now sit an unassailable 10 points behind Flu, were 2-1 victors over Sao Paulo in an entertaining affair at the Olimpico Monumental.
The hosts conceded a first half penalty which was dispatched by Rogerio Ceni before Andre Lima and a late goal from Marcelo Moreno saw Gremio over the line.
Ronaldinho got himself on the scoresheet in Atletico Mineiro's 1-1 draw away to Vasco da Gama.
The former world player of the year scored a 27th minute penalty before Alecsandro struck in the 56th minute to ensure his side enjoyed a share of the spoils.
In other results, Ponte Preta and Flamengo both enjoyed 1-0 wins over Internacional and Nautico respectively, Cruzeiro were too strong for Bahia in their 3-1 win while Figueirense played out a 1-1 draw with Sport Recife.