Naoya Inoue overcame a brief scare to move forward in his quest to create history.

The three-division and reigning lineal/WBA/WBC/IBF bantamweight champion needed two tries to make weight for his undisputed championship with WBO titlist Paul Butler. Both boxers ultimately hit the mark ahead of a fight that—barring a draw or No-Contest—will crown the first-ever undisputed bantamweight champion in the three or four belt era.

Inoue officially checked in at a ripped 117 ¾ pounds, surprisingly under the limit on the second attempt after initially weighing 118.1 when taking the stage on Monday afternoon (local time). Butler weighed in right at the divisional limit of 118 pounds on the first try, met with raucous cheers from his camp on hand to witness the event.

The two collide for all of the divisional hardware on Tuesday evening local time at Ariake Arena in Tokyo (ESPN+, 2:30 a.m. ET).

In addition to crowning the first four-belt undisputed bantamweight champion, Yokohama’s Inoue (23-0, 20KOs) looks to become the first Japanese fighter to accomplish the feat at any weight.

No bantamweight has laid claim to undisputed status since 1973, when Enrique Pinder’s WBA/WBC reign ended with his being stripped of the WBC belt ahead of an eventual loss to Romeo Anaya.

As it relates to Monday’s weigh-in, Inoue will fittingly depart the bantamweight division after his fight with England’s Butler (34-2, 15KOs). The 29-year-old elite-level talent has set his mind to becoming a four-division champion but not without first going in the record books for his beloved country. Inoue has held major titles at junior flyweight, junior bantamweight and bantamweight, sporting a record of 16-0 (14KOs) in major title fights, excluding two bouts where a secondary WBA bantamweight belt was at stake.

The road to undisputed saw Inoue claim the IBF belt in a May 2019 second-round knockout of Emmanuel Rodriguez and the WBA ‘Super’ title in a November 2019 points win over Nonito Donaire. Both fight came as part of the World Boxing Super Series bantamweight tournament, which Inoue won outright following his victory over Donaire. He added the WBC strap in his rematch with Donaire, scoring a second-round knockout on June 7 to unify three titles and lay claim to the division’s lineal championship.

Butler, 34, officially became a two-time bantamweight titlist on May 4, twelve days after winning the interim WBO title following a twelve-round, unanimous decision victory over Jonas Sultan on April 22 in Liverpool.

The bout was to have taken place against then-WBO champ John Riel Casimero, for whom Butler was the mandatory challenger. Casimero was stripped of the belt after violating a fight week sauna rule with the British Boxing Board of Control (BBBofC). The development marked the second time in four months that the brash Filipino failed to meet Butler in the ring, having withdrawn from their scheduled clash last December in Dubai after suffering an ailment which landed him in the hospital on the morning of the weigh-in.

Inoue is a massive 50-1 favorite according to bet365 Sportsbook, which lists the visiting Butler as a +1400 underdog. The over/under is set at just 2.5 round, with Inoue a -1600 to win the fight inside the distance.

Jake Donovan is a senior writer for Twitter: @JakeNDaBox