Claressa Shields, right, punches Ivana Habazin during the fifth round of a women’s 154-pound title boxing bout in Atlantic City, N.J., on Jan. 10. (AP file photo)

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.

The Flint native 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 said. “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’ family reacted with varying degrees of disbelief when she told them about her decision over Thanksgiving. Her mother didn’t believe it, and her sister angrily warned Shields against trying to fight men (that’s not happening) — but her father and boyfriend both were excited for her.

Shields 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 intends to work her way up in competition level in 2021 with a series of one-off PFL fights.

Shields’ last boxing match was in January, but she isn’t quitting that sport: She plans to announce a new date soon for her postponed junior middleweight world title fight with Marie-Eve Dicaire in which she will attempt to unify four 154-pound championship belts.