Atlantic City, N.J. WBO heavyweight champion Wladimir Klitschko retained his title Saturday night, stopping 41-year-old Ray Mercer in the sixth round of a scheduled 12-rounder.
The up-and-coming Ukrainian (39-1) knocked down Mercer in the first round and cut him in the fifth, using a powerful left jab that kept the rugged Mercer on the defensive throughout.
In the sixth, Klitschko backed Mercer into the ropes and unloaded a hard right hand that snapped Mercer's head back and seemed to take the fight out of him.
Mercer (30-5-1) moved to the other rope but when Klitschko unloaded another flurry of punches and the blood streamed down Mercer's face. Referee Randy Neumann stepped in, ending it at 1:08 of the round.
"I never faced a guy with such a strong chin," Klitschko said. "It's the strongest chin in the world."
The performance by the 6-foot-7-inch, 243-pound Klitschko might cement his reputation as the heavyweight division's next big thing. He was powerful, quick, he took a punch Mercer cut him over the right eye and he fought with the kind of fluid motion that many eastern European fighters lack.
In stopping Mercer, he did what no other fighter had ever done. In knocking him down, he did what only one Evander Holyfield had ever done.
"I got beat, fair and square," Mercer said. "He caught me with a big punch in the first round and I never regrouped."
Punch statistics reflected the degree of domination: Klitschko connected on 193 of 429 punches, to 54 of 124 for Mercer, according to CompuBox.