Deontay Wilder shook off injury to retain his World Boxing Council heavyweight world title on Saturday as bloodied challenger Chris Arreola failed to answer the bell for the ninth round.

In front of euphoric home fans in Birmingham, Alabama, Wilder remained undefeated in 37 fights, notching his 36th victory inside the distance with the technical knockout. Arreola had absorbed immense punishment when his corner told they referee they wanted to call a halt.

He was bleeding from a cut on the bridge of his nose opened in the first round, and his left eye was nearly swollen shut.

Wilder dropped Arreola in the fourth round, and after the challenger made the count of eight -- assuring the referee he was good to go on -- Wilder rocked him again at the bell.

The win looked all the more impressive when Wilder said in a post-fight interview he had broken his right hand and torn a muscle in his right arm.

Wilder's manager/trainer Jay Deas says the fighter will undergo two surgeries. The first to take place on Monday for the right hand and then the procedure to fix the bicep injury will be scheduled after that.

“They're still doing some of that, still assessing the situation, but it looks like he'll have two surgeries,” said Deas to the Tuscaloosa News. “One surgery on his hand and one on his bicep. The hand surgery will probably be first.”

“Deontay hits too hard to be a human being. He's got the genetic build of a basketball player. The bones are a little smaller. Most of the heavyweights at this level are big, thick guys with really large bone structure. He hits too hard for his bone structure.”

“Deontay prefers to use the puncher's gloves because he's such a big puncher. We're going to have to use more of a protective glove. It takes a little edge off your punch but it's more protective of the hand.”