Warning: Video contains coarse language
Lightweight contenders Dustin Poirier and Michael Chandler exchanged words and were separated by security while cageside at UFC 276 on Saturday in Las Vegas.
Welterweight Gilbert Burns posted a video of the incident on Twitter. It's unclear how the altercation began.
The pair have gone back-and-forth in the media in recent months. Neither man has a fight booked.
Poirier is coming off a loss to Charles Oliveira in a lightweight title bout last December, while Chandler scored a "Knockout of the Year" candidate against Tony Ferguson in May.