Kevin Lee, Michael Chiesa brawl on stage at UFC press conference

Michael Chiesa didn’t take too kindly to Kevin Lee bringing up his mother. And then all hell broke loose.

Chiesa and Lee brawled on stage at the UFC Summer Kickoff press conference Friday in Dallas. The two will meet in the main event of UFC Fight Night 112 on June 25 in Oklahoma City. But things got started early, with Lee throwing — and maybe landing — a punch on Chiesa up on the dais.

It all started when Lee brought up Chiesa’s mother during the press conference.

“He’s gonna headline because of me,” Lee said. “After that, he’s going back to the prelims. But I just hope he shows up, because I know his momma’s got tickets.”

Chiesa responded: “Don’t you ever talk about my f*cking mom. … I’m gonna smack the f*ck out of your right now, don’t you ever talk about my mom.”

Chiesa then dropped the microphone and ran over to Lee’s side of the stage. Security held him back, but Lee approached and threw a right hand over a security guard’s shoulder. They were separated from there.

Security escorted both men from the stage. The two were brought back later for a staredown and though they jawed back and forth, nothing physical came of it. Lee and Chiesa are two of the top lightweight fighters in the UFC.

The press conference was held to feature all of the upcoming headlining fights for the UFC’s summer cards, through July.

It was the first real blows being thrown during a UFC press event since Jon Jones and Daniel Cormier went at it in 2014. Both got fines from the Nevada Athletic Commission (NAC) for the transgression. Conor McGregor and Nate Diaz were also fined by the NAC for throwing water bottles and energy drink cans at each other’s team last August.

It was immediately unclear if there will be penalties for Chiesa and Lee after this incident.