WBC world champion Deontay Wilder delivered a seventh-round knockout to stop Luis Ortiz in their heavyweight rematch.
Ortiz looked ahead on the judges' scorecards when Wilder (42-0-1) stunned his opponent with a powerful right hand at MGM Grand in Las Vegas.
Wilder and Cuban opponent Ortiz initially met in March 2018, when the American stopped the 40-year-old in the 10th round.
Following six imperfect rounds on Saturday, Wilder came up big to abruptly end the bout against Ortiz (31-2) and stay undefeated with his belt on the line.
Wilder also etched his name into the heavyweight history books by making his 10th WBC title defence – equalling Muhammad Ali's record of consecutive defences.
"With Ortiz, you can see why no other heavyweight wants to fight him," Wilder, who is slated to fight Tyson Fury in February following their dramatic draw in December, said afterwards. "He's very crafty, he moves well and his intellect is very high.
"I had to play around with him. I had to calculate certain moves and certain places. I was in and out, sometimes I backed up. I went back, I went forward.
"My intellect is very high even though I don't get credit for it. I took my measurement, I saw my shot and I took it."
Looking ahead to the future with Fury looming, Wilder added: "Then after that [Fury rematch], I'm looking for a unification bout. I want one champion, one face, one name, and he goes by the name of Deontay Wilder.
"The heavyweight division is too small to have so many belts lingering around. There should just be one champion; it's too confusing for the fans."