Claressa Shields already reigns over boxing with two Olympic gold medals and professional titles in three weight classes.
Her next world to conquer is mixed martial arts.
Shields has signed with the Professional Fighters League in a quest to become the first woman to hold simultaneous titles in both MMA and boxing, she told The Associated Press on Monday.
She will make her debut next year, and she hopes to have two or three MMA fights along with two boxing matches during 2021 before she attempts to win the PFL title in 2022.
"I'm not trying to do this for show," Shields told the AP .
"I'm really taking this seriously. I'm not thinking that just because my hands are better than everybody else that I'll win. I'm really going to strengthen the things that I'm weak at."
Shields realizes she faces a steep learning curve as she prepares to fight as a 155-pound lightweight in the PFL.
She is still relatively new to jiu-jitsu, wrestling and kickboxing: "I've never kicked anybody in my life, not even in a street fight!" she said.
But Shields is a singular athlete with a work ethic to match, and she is confident in her ability to master other forms of hand-to-hand combat with the proper training.
"I'm not going in here knowing I'm going to beat these girls just because I can outbox them," Shields said.
"I'm going to have to get away from takedowns. Take some kicks. Make some kicks. Take some knees. I have to get used to getting grabbed, because in boxing, when a girl grabs me, I dang near want to slam her.
"I really feel that me against any other woman, no matter what it is, she's not going to be able to beat me."
Many fighters have tried the move Shields is making in both directions. Champion boxer Holly Holm famously changed sports and knocked out Ronda Rousey to win a UFC belt, while Conor McGregor parlayed his UFC success into one wildly lucrative boxing match with Floyd Mayweather.
Shields' interest in trying MMA has been rumored for years, and she also expressed interest in taking on UFC champions Amanda Nunes and Cris "Cyborg" Justino in a boxing ring. Now that the talk is real, Shields is eager to do the work necessary to make her bold dreams into reality.
"I just want to be great at everything," she said.
"I hate losing. I haven't lost a fight since I was 17 years old. I'm not here for a good time. I'm here to make my presence known to everybody I get in the cage with. You're not getting in there and just fighting against a boxer. You're getting in there against one of the greatest women's combat sports athletes to ever live."
Shields, from Flint, Michigan, hasn't settled on a training regimen or a home MMA gym, but she wants "to train with some of the best MMA fighters and coaches (to) speed up my process," she said.
She has spoken to former UFC light heavyweight champion Jon Jones about training with him in Albuquerque, and she will talk to other MMA stars about training dates. Shields said she will rely on her trainers to tell her when she's ready to step into a cage.
Shields is already the undisputed middleweight champion, and she wants to become the first female boxer to hold that distinction in two weight classes. Shields is 10-0 as a pro boxer, and she isn't worried about the time she'll spend on MMA interfering with her boxing career.
"I can box in my sleep," she said with a laugh.
"That's what I was born to do. Boxing is just in me. I'll never forget how to box. Even when I'm 80 years old, a girl better not try me, because she'll still be in for a whole heap of trouble. ... When you get older, you learn how to train smarter, not harder. To train smart will be what I try to do throughout my whole MMA career."
Shields insists her primary motivation is to win belts in both sports, but she has acknowledged frustration with the boxing industry's inability to make her a star on the level of her male counterparts or MMA's top female athletes.
"I'm not upset with boxing, but boxing has always been a sexist sport," Shields said.
"Until they start treating the women fairly, women's boxing will never go to where we're supposed to go. Even men's boxing is at a standstill right now. That's because they just won't be fair, and the boxing gods see that.