Vasyl Lomachenko threw so many punches it was only a matter of time before the detail emerged of where the decisive blow landed.
Left side of the temple, a dazed and confused Nicholas Walters explained after telling referee Tony Weeks he could no longer continue fighting after seven rounds.
Ukraine's Lomachenko, in the first defense of his World Boxing Organization super-featherweight belt, precisely peppered Walters as the action continued and the round-long attack in the seventh proved too much for the former featherweight world champion from Jamaica.
"It surprised me [Walters] stopped, but he was going to get knocked out in the next round. He was gone. This kid would've taken him out," promoter Bob Arum said as two-time Olympic champion Lomachenko improved to 7-1 with his fifth knockout.
Throughout the bout at The Cosmopolitan of Las Vegas, Lomachenko swerved in and out, side to side, avoiding Walters' power and exploiting openings that increased after the early rounds.
His deceptiveness defused expectations that this would be a fight-of-the-year candidate, although after winning his belt in June with a fifth-round knockout of Puerto Rico's Roman Martinez, Lomachenko will be a fighter-of-the-year candidate.
"Good fighter, really strong, but he just stood there and made it easy for me" in the seventh, Lomachenko said. "I had my plan, knew it'd be about four rounds to figure him out, and then I went to work on him. He said he'd do this and that. In the end, he just quit."
En route to his first defeat, Walters (30-1-1) spent the fourth, fifth and sixth rounds frustrated by Lomachencko's sharpness and evasiveness.
To close the fifth, Walters stopped throwing punches, stepped away, shrugged and began walking to his corner.
Lomachenko's lasting flurry in the seventh started with a combination of punches to the head. He hammered a cornered Walters to the body, then threw another combination closed by a hard uppercut to the jaw. Three more hard punches to the head prompted Walters to try to hold Lomachenko, who wriggled free, seeking to unload more blows.
The next thing to happen was Weeks waving off the bout.
Boos rained on Walters, who was paid a $300,000 guarantee for the bout while Lomachenko earned $1 million.
Someone noted Walters is currently living in Panama, home to Roberto Duran, who made "No mas" ("no more" in English) famous.
"He caught me very hard right here," Walters said in the ring, motioning to the temple. "He's a great fighter. I've never been hit like that before. He's very fast, a great puncher and he hit me with great shots all over my body."
Lomachenko expected more.
"In the beginning, [Walters] was saying he's a gladiator, he's a warrior, he's here to hurt people and win. But after he quit the fight, I don't count him anymore as a fighter," Lomachenko said. "Yes, of course, I felt I hurt him in the seventh."
Arum had high praise for Lomachenko, 28, saying he'll push to have him fight as many as four times a year, starting with a possible renmatch with Orlando Salido, the Mexican former featherweight champion who handed Lomnachenko his lone loss in his second pro fight when Salkido showed up overweight.
After that, Arum said a Manny Pacquiao fight later in 2017 is possible.
"This is the greatest fighter in the world," said Arum, 85, who celebrated his 2000th career fight card. "In the next couple of years, he'll make a punctuation point. [Muhammad] Ali had tricks like this kid. Nobody has the whole package of skills, balance like Lomachenko. This is a real magician, somebody special."