Undefeated World Welterweight Champions Terence Crawford and Errol Spence Jr had a heated exchange in Oklahoma on Friday night.

Crawford was in town to watch former sparring partner Maurice Hooker defend his crown against Alex Saucedo, and 'Bud' bumped into Spence backstage.

Last month, Crawford made the first defence of his WBO belt against Jose Benavidez Jr, earning a knockout in the final round before stating he was ready to unify the 147lb division.

"I’m gonna crush you, and I’m gonna stop you,” said IBF Champion Spence. "That sh*t's gonna be easy work. I’m gonna stop you, easy. It’s gonna be easy work, I promise you."

"You got hurt by [Carlos] Ocampo. And you got hurt by Kell Brook," Crawford replied. "Wait until I hit you. You gonna look like Benavidez."

"He had one leg,” argued Spence, referencing Benavidez's injury from being shot in the leg two years ago. "But I’m solid."

"I’m gonna make you do the Stanky Leg," warned Crawford.

Spence: "What you wanna bet on that? I’ll bet $100,000 on that."

Crawford: "Let’s bet $1 million."

"Let’s bet $ 1 million. Easy," Spence agreed. Both men then shook hands.

While Crawford's next opponent is unconfirmed, Spence will defend his belt against Mikey Garcia - coming up two weight divisions - in March.

Fans will be hoping promotional differences can be put aside, because Crawford v Spence is one of the best fights to be made in 2019.