FLINT, Mich. -- Claressa Shields has entered a league of her own.

The undefeated world champion boxer captured the undisputed heavyweight title with a unanimous decision victory over previously unbeaten Danielle Perkins on Sunday night.

She dropped Perkins (5-1, 2 KOs) with a right hook in the final seconds of the 10th and final round to secure the victory, but the fight almost didn't happen.

Shields (16-0, 3 KOs) pushed through a shoulder injury entering the match and couldn't lift her left arm for two or three days.

"I actually think I'm going to have to have surgery on my left arm. I tore my labrum last week, so the fight almost didn't happen," Shields said. "I didn't want to let Flint down, but I really couldn't use my jab the way that I wanted to, but I didn't the best that I could. I iced it, I did therapy and now I think I'm going to have a shoulder surgery."

Shields still managed to connect on 29% of her punches, and 36% of her power punches, according to CompuBox Stats while Perkins only landed 19% of her punches. The judges scored the fight 97-92, 99-90, and 100-89 all for Shields.

With the win, she became the first boxer, male or female, in the four-belt era to become the undisputed champion in three different weight classes (junior middle, middle and heavyweight).

She holds the WBC, WBA, IBF and WBO heavyweight titles. For women's boxing, the heavyweight division is considered 175 pounds and up.

In her heavyweight debut on July 27 in Detroit, she also scored a second-round TKO victory over Vanessa Lepage-Joanisse with Perkins on the undercard.

"I felt strong in there, but I know Danielle Perkins felt stronger. That girl was strong as hell," Shields said. "She was strong, she was definitely a problem. My experience and my skills got me over it and also, I've been in plenty of street fights with bigger people and I had to use some of my skills in that today, too. So, when I dropped her in the last round, it's because she got greedy."

She scored the bout's lone knockdown in waning seconds of the tenth round, but she also wobbled Perkins during the third round with an overhand right while connecting on some big right hooks as well. The crowd chanted "Whoop that trick" from the Hustle & Flow soundtrack as Shields landed those big shots.

"Flint is a different type of place. I can tell you that the people that we have here, they are fight fans for one. They're so supportive and they take you for who you are," Shields said. "So, them even saying, 'Whoop that trick,' you will never hear that in no other women's boxing match ever in history because it's just not even something that people even accept coming from women.

"People accept that from me here, coming from Flint and they understand me, and they know that I'm just as hood, just as street, but I'm also business and savvy and I'm very smart so they accept me for the full package, and I just love them so much for that."

Shields said she passed on an opportunity to fight at Barclays Center in New York so she could return to Michigan for a homecoming bout at the Dort Financial Center in Flint. During her ring entrance, she was joined by rapper Papoose and fellow undisputed champion Terence Crawford was among those in attendance.

Crawford said he was happy to support Shields in making history as the first-ever undisputed women's heavyweight champion of the world.

"I think it was a great fight. Perkins came to fight, she put up a good fight. She was big, she was strong. Claressa had the speed, timing and experience," Crawford told ESPN. "And at times, when she had to dig deep and make it a dog fight, I felt like she won that transaction as well. The whole turnout was a good night."

Shields, 29, is ESPN's No. 1-ranked heavyweight and No. 1 pound-for-pound fighter but said the fire still burns inside her to cement her place in history, even as she has been dubbing herself the "G.W.O.A.T" -- Greatest Woman of All-Time.

Sunday's bout also marked Shields' first time entering the ring since the December launch of her biopic, "The Fire Inside."

"It ain't enough. That's how I think. I think that I didn't get my flowers for so many years so even though I'm getting them now, it's like that's not enough," Shields said. "I deserve more than that. I'm fighting for a million dollars. So. I'm supposed to be getting paid five. This ain't it. So, for me, that's where the fire comes from."