At a Cage Fury FC BJJ event in Philadelphia on Saturday, Emily Hansen faced Amanda Mazza in a six-minute strawweight bout. Two minutes into the fight, Mazza was in good position, attacking Hansen with a rear-naked choke, but then the bizarre happened.

As Mazza looked to secure the choke, her arm appeared to make a gruesome pop, leading to confusion all around.

Check out the strange sequence below.

Referee Vitor “Shaolin” Ribeiro stepped in to make sense of the situation and the fighters were soon reset with Mazza in back control, but seconds later they realized something was wrong. The bout was then stopped due to an injury to Mazza’s arm.

The extent of the injury is unknown, but Mazza later posted a message to her Instagram Stories joking about the incident.

“Thank you everyone for the love and sweet messages,” Mazza wrote. “I’m still smiling and will be back and better. That mat return though, damn I felt good out there.

“So good I didn’t even feel my arm crack on her chin.”

According to both fighters, they initially stopped fighting because Mazza thought the popping sound was due to Hansen suffering a jaw injury. As it turns out, Hansen was just fine and it was Mazza who needed immediate medical attention afterward.

“Ummm, so I won by iron chin tonight,” Hansen wrote on Instagram Stories. “In all seriousness, this was not even in the realm of possibilities for tonight. Amanda is such a good person that she stopped because she thought it was my jaw that popped. I wish her a quick recovery and maybe we can run it back.”