Mexican side Toluca claimed a surprising 2-1 win at Boca Juniors and to top Group One of the Copa Libertadores after the first round of matches.
Toluca came back from a goal down and a missed penalty to win the game and become the second Mexican team to beat Boca at La Bombonera after Cruz Azul won 1-0 in the 2001 finals.
A 22nd-minute penalty by Santiago Silva put six-time Libertadores champions Boca ahead and the game looked comfortable when Boca keeper Agustin Orion saved a Carlos Rodriguez spot-kick in the 51st minute.
Eight minutes later, though, Toluca equalized as Carlos Esquivel received a long pass and netted a right-foot strike.
And in the 72nd minute, Sinha assisted Edgar Benitez, who shot over Orion's body for the winner.
In the last minute of the game, Boca striker Lucas Viatri could have equalized but his shot from outside the box hit the right post.
Toluca playmaker Sinha told Fox Sports: "Playing here at La Bombonera is very tough as Boca have huge tradition in this tournament.
"With dedication and effort you can build big teams. We know that winning away in the Copa Libertadores is very good."
Boca midfielder Cristian Erbes, meanwhile, said: "We are angry because we wanted to win our first home game in the championship.
"We must think about the mistakes we made and correct them."
A duel between Brazilian compatriots saw Atletico Mineiro beat Sao Paulo 2-1 in Group Three.
Two assists by veteran playmaker Ronaldinho helped Atletico Mineiro celebrate the win after a 13-year absence from the Copa Libertadores.
Jo opened the scoring in the 13th minute, while Ronaldinho dribbled past two Sao Paulo defenders before setting up Rever to double the gap in the 27th.
Aloisio reduced the gap with seven minutes to go.
Another Brazilian team to win was Fluminense as they saw off Caracas 1-0 in Venezuela, Fred scoring the winner in the 31st minute.
In Chile, Uruguayan giants Penarol claimed an important 2-1 win at Iquique in Group Four.
Fabian Estoyanoff and Juan-Manuel Olivera, one in each half, scored for the winners, while Manuel Villalobos netted the temporary leveller.
Finally in Peru, hosts Real Garcilaso and Colombian champions Santa Fe drew 1-1.
Cristian Martinez put the visitors ahead in the 15th minute, but Rolando Bogado leveled with a header in the 75th minute in Group Six.