Atletico Mineiro came from behind to beat the 10 men of Sao Paulo 2-1 away from home in the first leg of their all-Brazilian Copa Libertadores Round of 16 tie on Thursday.
Cheered on by their fans, Sao Paulo took control of the game early on through Jadson's eighth minute opener, with the striker finishing after good play from Aloisio and Ganso.
Ademilson came off the bench to replace Aloisio but then spurned several chances to increase the lead.
Sao Paulo's fortunes turned in the 35th minute when Lucio was sent off for a rash challenge on Bernard, and Atletico Mineiro responded.
Ronaldinho headed them level four minutes before half-time and just before the hour mark Diego Tardelli struck what proved to be the winner from Marcos Rocha's assist.
"The match was going in one direction but the red card turned it into something else," Sao Paulo's captain and goalkeeper Rogerio Ceni said. "When two similar teams clash, the loss of any player can be fatal. It's a pity, but we will look at what we can do for the second leg."
In Ecuador, a late penalty gave Emelec a 2-1 win over Brazilian giants Fluminense.
Emelec began brightly, with Marcos Mondaini striking the crossbar only three minutes in before further chances for Enner Valencia and Mondaini again.
They finally got the breakthrough in the 32nd minute but needed Fluminense Leandro Euzebio to score an own goal on their behalf.
But the Brazilians were level before the break with Wagner firing home after Emelec failed to clear their lines.
An even second half turned in the 85th minute when Carlinhos fouled Mondaini in the penalty area and Fernando Gaibor dispatched the spot-kick.