 Wladimir Klitschko (right) looked tentative at times |
Wladimir Klitschko survived a knockdown to beat DaVarryl Williamson on points after the heavyweight bout was stopped following an accidental head butt. Klitschko won by a split decision after the ring doctor halted the fight at the end of the fifth round in Las Vegas.
The Ukrainian had suffered a deep gash over his right eye following the clash of heads during the fifth.
Two judges had Klitschko ahead at the time of the stoppage with one judge putting Williamson in front.
Williamson, who had knocked down Klitschko in the fourth round with a right to the head, was unhappy with the outcome.
"This is unfinished business. We should do it again," he said.
However Klitschko played down the knockdown saying: "I was off balance and he caught me with a right hand.
"I built my fight with my left jab. I was using both hands well and I wanted to continue the fight."
Earlier, America's Jeff Lacy won the vacant IBF super middleweight title by beating Canada's Syd Vanderpool when the referee stopped the fight in the eighth round.
Lacy is now unbeaten in 18 fights.
Also on the undercard, Uganda's Kassim Ouma won the IBF light middleweight crown over Verno Phillips following a unanimous decision by the judges.
The bout had been Phillips' first title defence.