Naoya Inoue was never going to be denied history. 

A one-sided march was capped with a highlight reel finish for Yokohama's Inoue, who scored an eleventh-round knockout of England's Paul Butler to fully unify the bantamweight division. A rapid fire combination willed Butler to the canvas, forcing the knockout finish at 1:09 of round eleven in their lineal/WBA/WBC/IBF/WBO bantamweight championship Tuesday at Ariake Arena in Tokyo. 

With the win, Inoue becomes the first fighter from Japan to claim undisputed status in the three- or four-belt era. 

"This is the proudest moment of my career," Inoue humbly stated during his post-fight interview following his ESPN+ aired victory. 

Butler wisely spent the opening round circling the ring, forcing Inoue to come forward and find him. It didn't take long for Inoue to accomplish that goal, as he effectively cut off the ring and was able to fire off combinations. The defensively responsible was able to pick off most of the incoming, though Inoue managed a left hook around the Brit's high guard in the final minute. 

Inoue made the ring a very small place at the start of round two. Butler briefly stood his ground and doubled up on the jab before finding the space to once again employ lateral movement. Inoue was repeatedly successful with combinations ending with a left hook to the body. Butler landed a jab upstairs but a follow-up left hook was effortlessly dodged by Inoue inside the final minute. 

The first minute of round three saw the 34-year-old Butler cornered but able to defend against a swarm of right hands by Inoue. As was the case in the preceding rounds, action was largely one way as Inoue went on the attack and Butler remained on the defensive. It briefly changed in the closing seconds, where Butler connected with a double left hook to the head and body.

The same pattern held true in round four, though with Inoue throwing his left hook with greater frequency. Butler was once again able to minimize the impact but was unable to offer anything in return to earn Inoue's respect. 

Both fighters worked largely behind the jab in round five. Inoue threw it as a weapon as he stalked his prey, while Butler used it to set up combinations. Butler managed a lead right but was short with the left hook with just more than a minute to go. Inoue picked up the pace down the stretch, connecting with his own left hook. 

Inoue went southpaw for the first minute of round six before switching back to a conventional stance. Butler enjoyed his best moment as he landed a double left hook upstairs. Inoue openly mocked Butler's largely defensive approach, hopping in reverse and daring the visiting titlist to engage. 

The flow of the fight did not change in the second half. Inoue stopped punching for a moment in round seven to throw his arms in the air and wait for Butler to stand and fight. Butler landed a pair of power shots upstairs while along the ropes, which Inoue took well. 

A right hand by Inoue briefly stopped the mobile Butler in his tracks early in round eight. Butler stood his ground and fired off a right hand and left hook upstairs. Inoue went back in stalker mode, even putting his hands behind his back in looking to set a trap. A combination by Butler was met by a jaw-rattling right hand counter by Inoue. 

The bell sounded to begin round nine, the first time for Inoue since his Fight of the Year-level win over Nonito Donaire during their first meeting in November 2019. Inoue began to settle in for the possibility of going all twelve rounds for just the third time in his storied career as Butler showed a sturdy chin and sound defense. 

Inoue changed that in an instant once the fight entered the championship rounds. 

Butler forced to defend a vicious body attack by Inoue early in round eleven. A right hand up top set up the left hook just above the belt, once again forcing Butler to go on the move. Inoue trapped Butler along the ropes with a right hand to the body, setting up a flurry of power shots upstairs until Butler collapsed to the canvas. 

Referee Bence Kovacs stood over Butler as he completed his count, with Butler never a threat to make it to his feet.

Inoue was ahead 100-90 on all three scorecards at the time of the stoppage. Compubox's unofficial punch stats had Inoue landing 151-of-665 total punches (22.7%), compared to just 38-of-301 (12.6%) for Butler, who didn't land his first punch of the fight until the second round. Butler did not land more than eight punches in any round, while Inoue hit double digit connects in all but the ninth round, where he was credited with landing nine punches.

Butler (34-3, 15KOs) is once again one-and-done as a bantamweight titlist. The Ellesmere Port, Cheshire native claimed the interim WBO bantamweight title in a twelve-round win over Jonas Sultan on April 22 in Liverpool. The reign was upgraded to full title status on May 4 after originally scheduled foe John Riel Casimero was stripped for failure to defend.

Butler previously held the IBF bantamweight title, which he vacated immediately after his June 2014 win over Stuart Hall as he sought to win a belt at junior bantamweight. It ended in a knockout loss to Zolani Tete before returning to bantamweight, where his lone other loss came in a twelve-round decision to Puerto Rico's Emmanuel Rodriguez in their May 2018 vacant IBF title fight. 

Inoue advanced to 24-0 (21KOs), including an incredible 19-0 (17KOs) in major title fights spanning three weight divisions. The journey began with an April 2014 knockout win of WBC junior flyweight titlist Adrian Hernandez, quickly becoming a two-division titlist by year's end after annihilating long-reigning WBO junior bantamweight champ Omar Narvaez inside of two rounds in December 2014. 

A pound-for-pound run was already established by the time Inoue arrived at bantamweight in 2018. A first-round knockout of Jamie McDonnell saw Inoue collect a secondary version of the WBA title, which he brought into the World Boxing Super Series tournament. The first true title win at the weight came in the WBSS semifinals, when he slaughtered Rodriguez inside of two rounds to claim the IBF belt. 

Inoue won the tournament outright with a twelve-round win over Donaire, who held the WBA 'Super' belt at the time of their memorable November 2019 clash at Saitama Super Arena in Saitama, Japan. The same venue hosted their rematch this past June 7, by which point Donaire was more than a year into his WBC title reign before conceding the crown to Inoue inside of two rounds. 

Tuesday's win completed a goal of becoming Japan's first-ever undisputed champion in the four-belt era, now with the goal of doing so in two weight divisions. 

"I am honored to become undisputed champion at bantamweight," Inoue said after the fight. "This is my last fight at this weight. I am excited to see what is in store [at 122 pounds]."

Jake Donovan is a senior writer for Twitter: @JakeNDaBox