Wladimir Klitschko defended his four heavyweight belts at Madison Square Garden on Saturday, the Ukrainian defeating Bryant Jennings in a unanimous decision.
Klitschko improved to a 64-3 record as he inflicted Jennings' first defeat in his professional career, the American previously unbeaten in 19 bouts.
The judges scored it 116-111, 116-111 and 118-109 in favour of the WBA, WBO, IBF and IBO heavyweight champion.
Klitschko was taken the distance for the first time in three appearances in the ring, with Jennings surviving the 12-round bout despite taking a severe hit in the final three minutes.
It was Klitschko's 22nd straight win, one the 39-year-old claimed was "very competitive".
Jennings refuted the judges' assessment of the contest.
"I was taking his shots. Did he hurt me? Maybe," Jennings said.
"But I think the scorecards were way off ... that margin, I don't agree with it."