Video: Corinthians beat Flamengo 4-0 in Brazilian Seria A
Corinthians began the day fifth in the Brazilian Seria A table and looking to keep up with leaders Cruzeiro and Gremio.
The opponents Flamengo, managed by former Brazilian coach Mano Menezes, was also returning to one of his old sides.
Corinthians took the lead in the 25th minute when Romarinho exchanged passes with Douglas and then found Alexandre Pato and the former AC Milan applied the finish.
A long through ball from Douglas found Pato on the right in the 35th minute and the Brazilian international rounded Felipe in the Flamengo and scored from a very tight angle, for his sixth goal of the season.
Flamengo were poor and rarely threatened, the game was put beyond them in the 75th minute as Edenelson cross caused problems, the ball fell eventually fell to Pato and his thunderous volley was saved, only for Romarinho to tuck in the rebound.
A bad day got worse for Flamengo when Joao Paulo was adjudged to have fouled substitute Emerson in the area.
Replays showed that Emerson may have been a little theatric to win the spot kick.
Guerrero converted the penalty to wrap up a 4-0 win for Corinthians.
Corinthians have beaten Flamengo 4-0 in the Brazilian Seria A.
Brazilian international Pato scored a brace, with Romarinho and Guerrero getting a goal apiece.