A world title fight between Claressa Shields and Ivana Habazin has been called off after a sickening attack on James Ali Bashir at the weigh-in.
Habazin's veteran trainer was knocked unconscious and left in a pool of blood after being stuck by an unidentified person who fled the scene.
Two-time Olympic gold medalist Shields was set to bid to become a two-weight world champion in just her 10th professional fight with the bout taking place in her home town of Flint, Michigan.
But the horrific incident, which came after tempers flared at the weigh-in, has led to the fight being postponed.
Bashir, who previously worked with Wladimir Klitschko, was reportedly unconscious for around 2 minutes, being taken to the McLaren Medical Center and accompanied by Habazin.
Habazin posted a heartbreaking photo of her holding his head as he lay prone on the ground as she stated he requires "delicate facial reconstruction surgery" and has been moved to Henry Ford Hospital.
Habazin wrote on Facebook : "With deep regret my trainer James Ali Bashir was punched in the back of his neck by someone in Shields entourage.
"Bashir was taken to a local hospital and has now been moved to Henry Ford Hospital because delicate facial reconstruction surgery must be performed.
"I want to say that security was nowhere to be found. Club shows are run better than this organization.
"Clarissa has a big mouth and the people around her like Clarissa are always looking for trouble. Clarissa and her team are classless.
"During the pre weigh-in my coach wanted to look at Clarissa’s weight and her sister and Bashir exchanged words. Her family and friends should have never been allowed on the stage.
"Someone from her camp (suspect isnin jail) attacked my coach and sucker punched him. Bashir hit the floor face first and was bleeding and unconscious. The attacker quickly ran out of the building.
"I was in the hospital till 2 am, 12 hours. My immediate concern was to look after the well being of my coach. I think most people with a heart would do the same.
"We have been receiving threats and people are saying I am scared to fight because Clarissa is going to beat my ass. We don’t feel safe here.
"Claressa showed concern for my coach and she said she is sorry. But, then she called me out saying that I can't be looking for excuses and that I can take another coach. Seriously?
"I have this message for her: You can run your filthy mouth all you want. When my trainer recovers it will be just you and me in the ring.
"I want to see how tough you are when the entourage you hang out with aren’t there to help you. You’re going to find out just how scared I am of a classless fighter like you. Our day will come Claressa!"
A statement from governing body the WBC said: "The WBC strongly condemns any act of violence in any event related to our sport, and specially the horrible attack which took place in an official activity surrounding this event.
"The WBC is certain that the corresponding authorities will apply the full extent to the law to this regrettable incident.
"The WBC will monitor the investigation and resolution of the case, and will then determine if an actionable WBC violation of any WBC rule, regulation or code of ethics took place."
