ATLANTIC CITY — Shimmering in a gladiator-style boxing outfit, Claressa Shields paused for dramatic effect while her female entourage attached her cape and placed her crown on her head. Then she exploded into a shimmy and strode toward the ring as “Run the World (Girls)” blared.

Everything about the walkout for Shields’s Jan. 10 title fight here was a high-decibel, deftly choreographed declaration of female power — inspired, and soundtracked, by Beyoncé.

At stake that night, in her fight against Ivana Habazin of Croatia, were the vacant WBC and WBO female super welterweight titles. With a win, Shields would become the fastest boxer in history, male or female, to win world titles in three weight classes — in her case by shedding weight, rather than packing it on, to vanquish successive opponents at 168, 160 and 154 pounds in just 10 career fights.

The fight also represented a watershed moment for Shields, who plans to start training for a potential debut in mixed martial arts as early as 2021. Her plan to become a two-sport star is audacious. But for all her braggadocio in the ring, she’s humble about the multi-disciplinary mastery required to excel in MMA. Over the coming months, she pictures juggling both — burnishing her boxing résumé while training with experts in kickboxing, jiujitsu, wrestling and other MMA disciplines.

It’s an undertaking that raises a weighty question about the future of women’s boxing: Are there enough worthy contenders to continue challenging boxing’s self-proclaimed Greatest Woman of All Time?

“I’m better than all of them,” Shields, the only American to win back-to-back Olympic boxing golds before turning pro, said Friday night. “It doesn’t mean there’s not a large amount of women out there who can compete and try. But they’re all gonna fail!”

Habazin was next in line.

Bad blood

Boxing will always be Shields’s first love. A native of Flint, Mich., she has been training since she was 11, seeking refuge from a childhood of poverty and abuse. She remains committed to getting better, she said last week, while raising the profile and purses of women’s boxing.

She was guaranteed $300,000 for fighting Habazin. That’s a fraction of the $4 million purse WBC heavyweight champion Deontay Wilder got for his 2018 title fight against Tyson Fury. And Wilder reportedly took home $10 million once his share of pay-per-view revenue was added.

In the nascent arena of women’s combat sports, MMA generates more buzz and fatter purses than boxing. That’s part of the allure for Shields, 24, who was a heavy favorite as last week’s title fight against Habazin approached.

The bad blood was palpable. It had been building since June, when a knee injury forced Shields to put off a fight scheduled in her hometown. Habazin suggested Shields was faking because she couldn’t make weight. Shields lampooned her 29-year-old challenger on social media as a “HAZ-BEEN” and put clown-face emojis on her photos.

That fight was rescheduled for October, again in Flint. But at the weigh-in the day before, Habazin’s 68-year-old trainer, James Ali Bashir, was attacked with a sucker punch that knocked him face-first on a concrete floor, shattering several bones and requiring multiple surgeries. Bashir is still recovering. Shields’s brother, Artis J. Mack, was charged in the assault. He pleaded not guilty.

They rescheduled again, this time for Atlantic City. At the weigh-in last Thursday, security was heavy, and attendance was restricted. Habazin went first, stepping onto the scale in leggings and a T-shirt while eating a cup of ice cream with a spoon. It was a silent mockery of Shields, for whom slimming down to 154 pounds was a challenge.

Shields followed, taking off a blue velour warmup with “GWOAT” embroidered on the back to reveal her cut physique in an orange bikini. The scale read 153.4. She flexed her biceps, then posed for photos with her cache of title belts.

“It’s going to be two more belts after we’re done,” Shields proclaimed, predicting Habazin wouldn’t last more than six rounds. “She’s soft.”

Shields celebrated by downing a plate of spaghetti afterward. That night, she called her trainer, former middleweight champion John David Jackson, who had just propped up his feet to watch the news in his hotel room at Ocean Casino Resort.

“I want to go work out,” she said. She was worried she had been so focused on shedding weight that she had gotten rusty with her glove work. They met in the lobby at 9 p.m., along with Shields’s best friend, Jeaneia “Nene” Zamora, and her mentor, “Miss Corey” Taylor. They are the mainstays of Shields’s team — trusted advisers and, on fight nights, “belt girls” who walk her out to the ring.

Amid clanging slot machines and flashing neon, they paraded through the casino searching for an available room, eventually finding a security guard with a set of keys. By 10 p.m., Shields was stretching, jogging and shadow boxing in a dimly lit conference room, while Miss Corey and Nene mimicked her moves and giggled.

Shields amped up the intensity of her punches and proclaimed herself ready at 10:30 p.m. While Jackson taped her hands, she sang along with Sam and Dave to “Hold On, I’m Comin,” a favorite on the smartphone playlist that’s a staple of her workouts. Jackson laced up her oversized practice gloves with her nickname, “T REX,” on the cuff — 16 ounces, compared with the 10-ounce gloves she fights in. He slipped on his pads, and they went to work.

“Use your jab!” Jackson urged. “This girl says she wants to knock you out. If she stands in front of you, use your jab! Blind her with the jab, set up the right hand, then, bang! Bang! Bang all night.”

By 10:55 p.m., Shields’s face glistened with sweat. Jackson squirted her mouth with water and took off her gloves. She headed back to her room for a shower, some Melatonin gummies and one last round of shadow boxing before bed.

“It was for her mind, that’s all,” Jackson explained later. “If it made her feel comfortable and at ease, why argue with it?”

Heating up

“Today is doomsday!” Shields brayed the morning of the fight. “I’m fixing to beat the s--- out of this girl!”

She was padding around her ocean-view hotel suite in a pink chenille robe adorned with white hearts. The living room was packed with sisters, nieces, a nephew and friends, who kept the mood light. Shields had cranked up the heat; the air was warm and smelled of menthol and maple syrup, remnants of her Icy Hot lotion and breakfast.

The morning’s priority was getting the royal blue braids put in her hair, which is Shields’ way of spotlighting Flint’s ongoing water crisis at each fight. Jennifer Beady, who has braided Shields’s hair for the past 2½ years, had flown in from Flint for the job. She got to work, smoothing the 85-inch blue strands and carefully sectioning Shields’s hair for the two-hour procedure.

Shortly before noon, Shields’s chef delivered her snack: three hard-boiled eggs, oatmeal and a spinach-and-watermelon smoothie.

“She called me a bully!” Shields blurted out, her mind flipping back to Habazin. “No mas!”

Know her name

Ovation Hall holds roughly 5,000, but even with its upper tier blocked off, Friday night’s card wasn’t sold out. Boxing’s popularity in the United States has been waning since the 1950s. Atlantic City isn’t the title-fight mecca it was during the casino boom of the 1980s. And women’s boxing hasn’t captivated the sport’s older fans the way female MMA stars have caught on with that sport’s younger audience.

Nonetheless, Showtime, which has invested heavily in women’s combat sports, went live at 9 p.m., opening with a women’s welterweight bout that bloodied both competitors. It ended with the favored Alicia Napoleon-Espinosa, who had been penciled in as Shields’s next opponent, losing a close decision to Swedish super middleweight Elin Cederroos, a former soccer player and mother of two. Asked afterward whether she would like to face Shields, Cederroos hesitated. A savage men’s bout was stopped in the fourth round, extending Philadelphia welterweight Jaron Ennis’s record to 25-0 with 23 knockouts.

But most of the crowd had come to witness Shields-Habazin, the card’s headline event, including a contingent from Flint that made the 10-hour drive that morning. Chants of “T-Rex” rang out even before Shields appeared.

Habazin, dressed in Spanish toreador garb, walked out to boos, trailed by her former trainer, Bashir, who took a seat in the front row. With bleeding on his brain, he’s been unable to work, replaced in Habazin’s corner by a protege.

Then came Shields, the conquering gladiator.

“It’s time to eat!” one of her sisters yelled, standing on her seat. “T-Rex is fixing to eat!”

Shields started judiciously, feeling out her opponent in the early rounds yet dictating the predatory dance, leaning in as she stalked the Croat around the ring.

With each two-minute round, Shields got more aggressive, deftly slipping Habazin’s punches then firing back with direct blows, her hands flying in the 10-ounce gloves. She had vowed to drop Habazin in six rounds. A shout from a friend, 2004 Olympic gold medalist Andre Ward, seemed to provide the spark she needed.

“Sis, take her to the body!” Ward hollered from his front-row seat.

Shields landed a blast to Habazin’s ribcage that dropped her to a knee. It was Shields’s first career knockdown.

“You want that ice cream now?” someone in the stands taunted.

From there, it was all Shields, who landed nearly three times as many punches as Habazin — 141 to 49, according to CompuBox statistics — and finished the 10-round contest with barely a nick on her face. Habazin’s left eye and cheekbone were bloated and blood red.

The moment referee Sparkle Lee announced the unanimous decision, Shields’s manager, Mark Taffet, restored the crown to her head as she raised both fists.

“What’s my name?” Shields shouted.

“T-Rex!” the crowd replied.

“What’s my name!?”

“T-Rex!”

“What’s my name?”

The question now is whether Shields’s name will translate to the octagon.