IBF, WBO, WBA, WBC middleweight champion Claressa Shields says she's 100% confident she could beat male fighters ... and she's calling them out by name.

Shields unified her division last weekend when she dominated then undefeated Christina Hammer to win a ten round unanimous decision.

The 24-year-old sensation is now focused on landing the biggest fights possible, including a catch-weight showdown with Cecilia Braekhus.

The two fight at different weight classes but Shields says she's hoping they can meet at 154 pounds and battle it out to determine the greatest pound-for-pound fighter alive.

Shields doesn't just consider herself the best female fighter alive -- she thinks she's better than most male fighters too ... and she's willing to back it up.

"I spar with men. I drop men. I bust [men's noses]. I beat men up all the time," Shields said to TMZ Sports.

She believes that she can handle WBA welterweight champion Keith Thurman, and also believes that she can give former unified middleweight king Gennady Golovkin a run for his money.

"I think I can beat up Keith Thurman ... I really do," Shields said.

"They may be stronger than me, but their boxing ability isn't like mine. GGG, he's older now, but I could give GGG a run for his money."

"Power for power isn't a question because what is boxing? Boxing is the sweet science. It's not about strength ... because people were saying Christina Hammer was stronger than me. They were saying all these girls were stronger than me, but did you not see the head movement that I had during the fight? See the defense? The offense? The traps I set?"

"If I were to get in there with a man, I would do a lot more of that. And, I do have some power. I'm not gonna say I'm stronger than them, but if I set up the right shots with the right timing?!?!"