The ring villain was hit in the back of the head during a staged stand-off with wrestling fans, and he turned and attacked the wrong guy.
A joint statement from Punk and his WWE bosses, obtained by the Los Angeles Times, reads: "Unfortunately, a few fans began shoving him and one struck him in the kidney and on the back. WWE regrets that proper security measures were not in place, and CM Punk apologizes for reacting in the heat of the moment."
The man he hit has filed a report with the Sacramento County sheriff's office.
The star, who also acts and plays in a rock band, took on CM Punk in the city on Thursday (24May12) and after his rival began waving the flag, Jericho snatched it from him, crumpled it up and kicked it out of the ring.
However, local police then stepped in to put a stop to the event as desecrating the national flag is a crime in Brazil, and Jericho was ordered to apologise or face punishment.
The star did as instructed and the match was allowed to continue, but Jericho has now been suspended indefinitely by chiefs at World Wrestling Entertainment for his actions.
A statement from WWE reads, "Chris Jericho has been suspended indefinitely due to an irresponsible act of denigrating the Brazilian flag at a WWE event in Sao Paulo on May 24. The WWE has apologised to the citizens and the government of Brazil for this incident."
Jericho adds, "I made a bad judgment call in the course of entertaining fans in Brazil. I apologised to the people in the crowd for showing disrespect. It was a bad move. I did it with fans' entertainment in mind and I'll accept the consequences for that."