NEW YORK -- Deontay Wilder survived a pummeling from Luis Ortiz, then knocked out the challenger in the 10th round Saturday night to retain his WBC heavyweight title. Befitting the undefeated champion from Alabama, it was a wild affair for the final few rounds after a dull series of pawing and gesturing by Wilder gave Ortiz a solid lead. Even after Wilder knocked down Ortiz in the fifth round, the bout remained in the Cuban's favour.

Then, in the seventh, Wilder appeared out on his feet though he never hit the canvas. He stumbled to his corner when that round ended, and the end seemed near for Wilder.

Instead, he closed the ninth with two hard rights, and then a series of vicious combinations in the 10th started Ortiz's downfall.

It was over with 55 seconds to go in the 10th after Ortiz went down for the second time in the round from a right uppercut and referee David Fields stopped it.

"I just had to get my range back and my fundamentals back," Wilder said. "And I was able to do that. I showed I was a true champion tonight."

Wilder, 32, is 40-0 with 39 knockouts. This easily was his toughest bout. Somehow, he was ahead on all three judges' scorecards.

The Associated Press had it 86-83 for Ortiz heading into the 10th.

Ortiz, 38, is 28-1. He couldn't have come much closer to becoming the first Cuban heavyweight belt holder after finally getting his match with Wilder. Their initially scheduled bout was in November, but Ortiz twice tested positive for a banned substance, a diuretic.

Wilder basically threw away the early rounds with a lack of aggression and much clowning. The left-handed Ortiz was all business.

In the fifth, with boos raining down from the crowd of 14,069 at Barclays Center, Wilder finally landed a solid punch. That invigorated him and two rights to the chin sent down Ortiz.

Wilder couldn't finish him, and was nearly finished himself two rounds later. Ortiz was so dominant in those three minutes that Wilder looked bewildered at his predicament.

The champ hung on in the eighth, then somehow found the fortitude and punching power to turn it around in the final two rounds.

"A true champion always finds a way to come back and that's what I did tonight," Wilder said. " Luis Ortiz is definitely a crafty guy. He put up a great fight. We knew we had to wear him down. I showed everyone I can take a punch."