With just minutes before the main event was slated to go on, Amanda Serrano was "medically unfit" to fight in her home country of Puerto Rico.
Most Valuable Promotions said Serrano suffered an eye injury on Friday, and the Puerto Rican Boxing Commission wouldn't clear her.
The promotion added that ticket refunds would be given to those who seek it, and Serrano's opponent, Nina Meinke, would receive her full purse.
CLICK HERE FOR MORE SPORTS COVERAGE ON foxnews.1eye.us
An emotional Serrano, with sunglasses on, said the injury occurred when she was getting her hair dyed earlier in the week.
MVP co-founder Nakisa Bidarian said a chemical from the hair dye went into Serrano's eye during a run on Friday. She wore sunglasses throughout Friday night's weigh-in.
"I wanted to fight in front of my people," Serrano said.
"I am so sorry. I came to fight and put on a show for you guys. I will be back."
Saturday was slated to be Serrano's 50th professional fight, and perhaps even a farewell. The event was at Puerto Rico's famed Coliseo, an 18,500-person arena, and Serrano said she "will retire" at the venue.
Jake Paul, the co-founder of MVP, explained that Serrano's cornea had been damaged from the chemical, which also burnt her hand, and there was too much risk in allowing her to fight.
Paul, who is normally the main event wherever he fights, took a backseat this time, telling Fox News Digital earlier this week that it was Serrano's "time to shine."
"I just always wanted that for her. This is her moment, and her time to shine," Paul said to Fox News Digital before Saturday's fight. "It’s just so cool to support her. She really deserves this moment and has worked so hard for it. I’m happy to be a fan. The pressure is off of you when you’re not the main event, but you hear the crowd is much louder for her out there. So that’s why this is her spot, her time to shine."
Serrano spoke with Fox News Digital last month and gave Paul the utmost thanks for allowing her to the main-event in her home country.
"He said this is my home, and he would never take that main event," Serrano said at the time. "I'm like, ‘No you can do it! You can do it!’ He's like, 'There is no way you’re going home, and you're going to showcase your home.'"
CLICK HERE TO GET THE FOX NEWS APP
Paul fought just prior to the cancelation and won via first-round TKO over Ryan Bourland.