American Gervonta Davis took his record to 28-0 with 26 knockouts on Saturday when he stopped previously unbeaten Hector Luis Garcia in a World Boxing Association lightweight fight.
Davis retained his WBA "regular" world title in the division, in which American Devin Haney is recognized as the WBA's "super" world champion.
Unbeaten Haney also holds the WBC, IBF and WBO belts, which he defended with a dominant victory over Australian George Kambosos in Melbourne in October.
Saturday's bout at the Capital One arena in Washington saw Dominican Garcia push Davis in the early going.
But Davis began to assert himself in the middle rounds.
At the end of the eighth -- after a brief timeout because of an altercation in the crowd at ringside -- Davis found Garcia with a punishing left.
Garcia didn't answer the bell for the ninth. He was heard saying "I can't see" in his corner and referee Earl Brown officially stopped the fight seconds into the ninth.
"I'm never surprised," Davis said of his reaction to Garcia's refusal to answer the bell for the ninth round.
"When I caught him, I knew he was hurt, he was hurt bad.
"He's a fighter, so he didn't want to show it."
Garcia, the WBA super featherweight champion from the Dominican Republic, fell to 16-1 with 10 knockouts.