Crawford defeated Spence via ninth-round technical knockout to become the first male to win the undisputed championship in two weight classes in the four belt era.

[6] In April 2019, Crawford defeated English boxer Amir Khan via technical knockout and called out Spence to a bout.

[9] He defeated Cuban boxer Yordenis Ugás via technical knockout and proceeded to call out Crawford.

"[13]That same day, Spence replied on Twitter stating; "[He's] been stalling for months I could’ve fought in November... been fighting at this weight for over a decade this shit ain’t easy or fun.

[15] On May 23, ESPN reported that Spence vs Crawford agreed to a July 29 deal fight for the undisputed welterweight championship in Las Vegas.

[16] On May 25, it was announced that Spence and Crawford would face each other on July 29 at the T-Mobile Arena in Paradise, Nevada for the WBA Super, WBC, IBF and WBO welterweight titles.

[20] After the fight, the IBF ordered Crawford to face its interim champion, Jaron Ennis.