When the referee signaled that the boxing match was over in Round 6 early Sunday, Jake Paul leapt onto the turnbuckles in a corner of the ring at Amalie Arena in Tampa, Fla., and stared into the screaming crowd. Then he turned toward one of Showtime’s cameras and took a bow.

His opponent, Tyron Woodley, lay facedown near the center of the ring after a powerful right hand from Paul had knocked him out.

In an interview in the ring after the fight, Paul, sweating and breathing heavily, declared himself “one of the most valuable boxers in the sport.”

“It’s got to be one of the greatest moments of my life,” he told his interviewer, Ariel Helwani. “Look at what I just did. Look at the year I just had. Unprecedented.”

Later, Paul, 24, addressed the Ultimate Fighting Championship’s president, Dana White, with whom he has publicly feuded, and offered to take on some of the stars of mixed martial arts, all of which would be enormous draws should any of the proposed bouts come to fruition.

Saying he had just “embarrassed your whole company,” Paul pleaded with White to accept his offer, which included facing mixed martial artists like Kamaru Usman, the current U.F.C. welterweight champion; Nate Diaz; Jorge Masvidal; and Conor McGregor. “I’m going to embarrass them, too. I promise you that, Dana.”

Woodley is a former U.F.C. welterweight champion who had successfully defended his title four times, eventually losing it to Usman in 2019. Woodley’s final four U.F.C. matches ended in defeat.

Whether Paul is a product of his social media following (22.1 million accounts follow him across Twitter and Instagram), his trash-talking or other promotional tactics, he has become one of the most popular, and polarizing, draws since he turned to boxing a few years ago. He had built up his fame as an actor on Disney Channel, then on Vine, a former video-sharing app.

Paul’s stock has risen tremendously in only five fights, and his ascension has been nontraditional. Combat sports purists resent his gimmicks. Others appreciate the spectacle and attention he and his brother, Logan, have brought to the sport.

In June, Logan Paul, a YouTuber like his brother, went the distance in an exhibition match against Floyd Mayweather, a bout that ended without a winner.

On Saturday night, Jake Paul, no stranger to garnering attention, walked out to the song “Y.M.C.A.” by the Village People, acting out the letters as the crowd sang along.

Paul (5-0) has now knocked out each of the four opponents he has faced. (He beat Woodley by split decision in August before knocking him out early Sunday.)

After a win in his first professional fight, in 2020 against a fellow YouTuber, Paul beat a former N.B.A. player, Nate Robinson, in a knockout, the videos of which went viral. He then blasted Ben Askren, a retired mixed martial artist, in the first round. None of his first three opponents offered much competition as boxers, or even punchers. After signing a multiple-fight deal with Showtime Sports, Paul scheduled Woodley, once one of the best welterweights in the U.F.C.

Paul had hoped to be taken more seriously in boxing when he faced Woodley in August. Although Woodley had fought only mixed martial arts bouts till then — 27 of them — they squared off at the N.B.A. arena in Cleveland, Paul’s hometown. Two of the three judges scored the close bout in Paul’s favor, but skepticism about his legitimacy remained.

After Tommy Fury, an undefeated boxer who is the brother of the heavyweight Tyson Fury, pulled out of their scheduled fight a few weeks ago because of a medical issue, Paul scheduled a rematch with Woodley and promised a more exciting match than the first one.

After Paul knocked him out in an otherwise dull fight early Sunday that drew boos from the crowd, Woodley commended him.

“At some point, you’re going to have to start putting a little respect on Jake’s name,” Woodley told reporters afterward.

After fielding criticism that he was too passive in their first meeting, Woodley was slightly more aggressive to start their second match. He threw more than 30 punches in the first round, compared with fewer than 10 in August. In the third round, he accidentally elbowed Paul in the forehead, opening a deep gash above Paul’s right eye that bled for most of the fight.

With less than a minute left in the sixth round, Woodley appeared to lower his left hand before Paul nailed him on the side of his head.

Afterward, Woodley said he did not know why he dropped his hand.

“Sometimes I just felt like I was too tense,” he said afterward, “and I may have dropped them just to breathe and loosen up.”

Paul, who has not faced a boxer in his short career, called out Fury repeatedly in the time leading up to this weekend’s fight and again afterward, telling reporters that Fury was “lucky he wasn’t in there tonight.”

His confident remarks continued throughout his news conference after the fight, where he emphasized his importance to the sport.

“No one in the history of boxing has done what I’ve done at this age,” Paul said.

But not everyone was convinced.

In response to Paul’s offer to face him next, Masvidal, who lost to Usman in their welterweight title bout this year, denounced Paul's proposition on social media.

“I fight for money or to fight the best in the world — you’re neither,” Masvidal said in an Instagram video. “I’ll tell you what. Come on over to U.F.C. Sign a one-fight deal. I’ll break your jaw in front of the whole world.”