In the middle of the chaos, a fan wearing a white top that appeared to have gotten torn during the scuffle got isolated. A fan in black then hit him with a left hook that knocked him out with his back on the floor.

The same fan that delivered the punch floored another with his left hand just seconds before. Meanwhile, surrounding fans made sure to put chairs aside as the brawl continued.

A fan got knocked out during a brawl at Arena CDMX during UFC Fight Night in Mexico City

Brandon Moreno’s rematch with Brandon Royval headlined the UFC’s return to Mexico City

A rematch between featherweights Yair Rodriguez and Brian Ortega served as a co-headliner

UFC chief Dana White admitted it was one ‘one of the craziest things he’s seen’ and was surprised security didn’t step in to stop it.

‘The crazy thing about that fight is it went on forever. I went over and was watching it – no one stopped it. I was waiting for security to come in, they just let it go until it was over.

‘I don’t think it was a bad look for the UFC. It happened and that was the end of that. I think after everybody else saw that shit, no one wanted to try that again. I’ve never seen any s*** like that in my life. Crazy.’

The event is the UFC’s sixth event in Mexico City and their first in the last four-and-a-half years.

The promotion’s return south of the border features two of Mexico’s former UFC champions on top of the bill. Former flyweight champion Brandon Moreno headlined the event against Brandon Royval.

Additionally, former interim featherweight champion Yair Rodriguez starred with Brian Ortega in the co-main event. The two previously squared off in 2022 at UFC Long Island. Unfortunately, Ortega injured his shoulder minutes into the fight, granting Rodriguez an anticlimactic TKO victory.

Earlier this week, the UFC opened its first Performance Institute in Mexico.

The UFC PI in Mexico City is a 4,636-square-meter, state-of-the-art facility. Its amenities include a weight room, grappling floor, nutrition lab, and physical therapy.

‘This has been a dream and goal of mine since 2001. To finally be here and walk the halls of the UFC Performance Institute in Mexico City is a monumental moment in the history of our sport,’ wrote UFC chief Dana White.

‘The impact this facility will have on Mexico, as well as, both Central and South America will be MASSIVE.’