Most Valuable Promotions has banned Claressa Shields from all future events following a physical altercation with Alycia Baumgardner on Saturday.
Both boxers attended MVP’s first mixed martial arts event as Ronda Rousey beat Gina Carano in just 15 seconds in California.
A video circulating on social media shows the pair arguing before Shields appears to reach out and hit Baumgardner.
Five-weight world champion Shields, who has been undisputed in three weight classes, later claimed on social media that Baumgardner had physically threatened her.
MVP said it is aware of the incident and that it holds a “strict zero-tolerance policy for hostile, threatening, or aggressive behavior”.
“Physical altercations outside the ring or cage are unacceptable in any MVP environment,” MVP said.
“MVP does not condone, tolerate, or accept Claressa Shields’ behavior in that setting and it reflects poorly on MVP and women’s sports, which we have worked tirelessly to uplift.
“Effective immediately, Claressa Shields is banned from all MVP events until further notice.”
Unified super-featherweight champion Baumgardner, 31, claimed the incident was “unprovoked”.
“I was physically assaulted without provocation,” Baumgardner said.
“This behaviour reflects a repeated pattern of hostility, chaos, and attention-seeking conduct that continues to embarrass women’s sports.
“This situation has been and will continue to be handled legally and professionally.”