Deontay Wilder has shifted his immediate focus away from a unification fight against Anthony Joshua, instead offering Luis Ortiz a shot at his WBC heavyweight title.
Wilder (39-0) and Ortiz (28-0) were due to meet in New York on November 4, but the Cuban was replaced by Bermane Stiverne after he failed a drugs test.
The 38-year-old returned to the ring with a second-round knockout of Daniel Martz on Friday and taunted the ringside Bronze Bomber, who responded by agreeing to a bout between the pair.
"I think you're one of the best and I want to prove I'm one of the best. So for the best to prove they're the best, the best must fight each other. So I'm going to bless you again with a second opportunity," Wilder told Ortiz after entering the ring.
"I'm always a man of my word. Luis Ortiz you will have your fight, I will bless you again. This time, no excuses.
"Make sure you train hard because I'm coming to whoop your a**.
"Every man that's stepped in the ring with me got knocked out, if you step in the ring with me I'm going to knock your a** out too."
WBO title holder Joseph Parker is expected to be next in line for IBF and WBA champion Joshua, with the New Zealander more willing than Wilder to accept a smaller share of the purse.