Demetrius Andrade dropped and stopped Luke Keeler in nine rounds to retain his WBO middleweight title in Miami.
Andrade dominated the Irish challenger in a successful third defence of his crown and afterwards targeted a world title in a third weight division by calling out WBO super-middleweight champion Billy Joe Saunders.
The American southpaw sent Keeler crashing to the canvas inside the opening five seconds and floored him again in the second round.
Keeler bravely battled back but Andrade resumed control in the eighth and hurt the Dubliner in the ninth with a big left before unleashing a barrage of blows to prompt the referee's intervention.
"I'm willing to go up to 168 to fight Billy Joe Saunders in my next fight and that's what I'm looking to do," said undefeated Andrade.
Saunders hit back via social media: "You won my vacant title. Nowhere near world level."
Austin 'Ammo' Williams showed off his explosive punching power during a TKO victory over Donald Sanchez.
The 23-year-old southpaw dropped Sanchez in the second round and twice more in the fourth to secure his fifth straight win in the pro ranks and fourth inside the distance.