Deontay Wilder (L) nails Artur Szpilka in January at Barclays Center. Photo: Naoki Fukuda

Deontay Wilder had the same surprised reaction that many fans had watching Charles Martin stumble badly against Anthony Joshua.

Wilder (36-0, 35 knockouts) admits he was frustrated by Martin’s performance, saying of the former heavyweight titleholder he basically gave up and was only thinking of a payday. Joshua stopped Martin at 1:32 of the second round when Martin curiously chose to rise off the canvas just as the referee counted him out on April 9.

“You always want to go with your countrymen,” Wilder said Tuesday at a public workout at his Skyy Gym in Northport, Alabama. “To be honest, Martin, he disappointed us all. Not only me, but a lot of people. You could tell that he didn’t want to fight no more. He could have gotten up. I think he felt he got hit harder than he’s ever been hit in his career and didn’t know how to mentally deal with that.”

Martin reportedly was paid millions of dollars to travel to England to make the first defense of his IBF title. Wilder is scheduled to make the fourth defense of his WBC title (first mandatory) against Alexander Povetkin (30-1, 22 KOs) on May 21 in Moscow, Russia.

There are obvious parallels between their situations — fighting away from home against a formidable opponent. But Wilder, a former U.S. Olympian, seemed disgusted talking about Martin’s efforts. Martin’s title reign of 85 days is the second shortest in heavyweight history, trailing only Tony Tucker’s 64-day rule as champion in 1987.

“He didn’t want to get back up and fight,” Wilder went on. “He thought about how he got the biggest payday of his career. I heard after the fight, he went home and bought a Bentley. Stuff like that, you don’t get far.

“Now he’s rated as the second-shortest term champion in history. That’s something I wouldn’t brag about or want to go down in history as. With that being said, I was very disappointed in him. That’s him.” Wilder paused and sighed. “I don’t even want to talk about him anymore.”

Wilder was more animated discussing his own fight. He seems to be taking a “knockout or bust” approach with Povetkin in Russia amid fears he may not get fair treatment from the judges. “We all know that if we knock him out then we don’t have to worry about that,” the titleholder said. “So of course that’s going to be my priority on my list — to knock him out.”

Wilder would have preferred the fight take place in the U.S. and for a time it appeared the bout may end up at Barclays Center in Brooklyn, which is owned by the Russian oligarch Mikhail Prokhorov. But Russian promoter Andrey Ryabinsky, who won the purse bid with a $7.15 tender, chose to place the fight in Megasport Arena (formerly known as Khodynka Ice Sport Palace) in Moscow.

“Like I said before, it’s easier for me to fight here in America but that’s not what it’s all about to me,” Wilder said. “When I have a title that says the heavyweight champion of the world, I want to travel all over the world to defend my title. I’m living my dream, I’m getting an opportunity to do that with this fight. I’m looking forward to Russia and I want to tell Russia, ‘Here I come.’ “