Boxing star Claressa Shields started off her mixed martial arts (MMA) career by winning against Brittney Elkin in her debut fight. 

Shield's debut match happened on Thursday night, June 10, as she gained a third-round TKO against Elkin at Ocean Casino Resort in Atlantic City, New Jersey.

USA Today reported that Shields fought in the 155-pound women's lightweight division while displaying her powerful punches. 

Claressa Shields wore red trunks and top, a different wardrobe compared to the flashy costumes she wore during her boxing fights, Associated Press reported.

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Claressa Shields Shows off Skills in MMA, Defeating Brittney Elkin

Brittney Elkin, a Brazilian Jiu-Jitsu brown belter, controlled most of the first two rounds, as the world champion boxer Claressa Shields displayed inexperience during takedowns. 

Shields, who has a record of 11-0 in boxing, shows a future in MMA as she now holds a record in the sport with 1-0. Brittney Elkin has a record of 3-7 in MMA.

The fight on Thursday did not start well for Shields. The Brazilian fighter took the boxing star down inside the cage early in the first round.

Claressa Shields also received a good pounding in the face from Elkin. During the second round, Elkin landed a big right punch that shook the boxing star a little bit.

Shields showed off her skills in punching during the third round as she got on top of her Brazilian opponent, letting her right hand finish the job. 

Claressa Shields revealed that she heard her coaches, saying "let her up," but what ran in the mind of the boxing star was "hell no."

"MMA was something like, 'It's possible I could lose this first fight. I don't want to lose. I'm going to try dang hard not to lose,'" said Shields, adding that she had a "never-quit attitude" every round.

Claressa Shields Before Winning MMA Debut Match

Before entering the cage of MMA, ESPN reported that the boxing star spent parts of the past six months training for mixed martial arts. 

Claressa Shields trained in Jackson Wink MMA in Albuquerque, New Mexico, the home of UFC stars such as John Jones and Holly Holm. However, she took breaks to continue her career in boxing.

Shields was a two-time Olympic boxing champion and a current three-division pro boxing titleholder. The boxing star won an Olympic gold medal in the 2012 Games in London and at the 2016 Games in Rio before turning into a professional boxer.

Meanwhile, CEO Peter Murray said that Shields would fight again this year in the Professional Fighters League (PFL), as the boxing star already signed a three-year contract with PFL last year.

"This is just her first step to prove herself that she has really what it takes to make the '22 season," the CEO of PFL said.

Despite confirming that MMA will be her focus, Shields noted that she will still fight in boxing before the year ends and continue participating in the sport. 

Claressa Shields is scheduled to have another MMA fight in August and is expected to join PFL's regular season in 2023.

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WATCH: Claressa Shields VS Brittney Elkin MMA FIGHT Highlights - From MECKLENBURG ILLEST