TOKYO — Here was a moment straight out of the great, old days of U.S. men’s Olympic boxing, with American lightweight Keyshawn Davis throwing a right like thunder at France’s Sofiane Oumiha in their round-of-16 fight Saturday afternoon.

Oumiha’s head jerked back. His eyes went glassy. His legs shook. He wobbled backward. He wobbled sideways. Then the referee waved his hands. The fight was over.

Davis ran around the ring inside Kokugikan Arena, waving his arms, celebrating what amounted to a rare Olympic knockout. As he ran, there came a sense that American men’s Olympic boxing might actually be coming alive again.

“I’m getting gold,” he declared later in a hallway beneath the arena’s stands. “That’s not really even a question. I’ve got no choice but to get gold. I’m getting gold, and that’s what I’m shooting for.”

It has been 17 years since Andre Ward became the last American male boxer to win an Olympic gold medal. Since then, the United States has earned just three men’s medals: Deontay Wilder’s bronze in 2008 and Shakur Stevenson’s silver and Nico Hernandez’s bronze at the 2016 Games.

Distant are the memories of the great U.S. teams of the past, such as the one led by Sugar Ray Leonard and Leon and Michael Spinks that won five golds, a silver and a bronze in 1976. Or the 1984 team, seen by some as the greatest ever, that had nine golds, a silver and a bronze. In the decades since, USA Boxing was slowly torn apart by shaky management; distrust between the national team coaches and fighters’ personal coaches; and the United States’ inability to adjust to the three-round, international, amateur style of boxing that favors quick punches over thunderous blasts.

But USA Boxing has slowly tried to heal itself, with new management and a full-time coach in Billy Walsh who has stayed through two Olympic cycles and sees potential for the American men. With Davis’s victory Saturday, the United States has three male fighters one victory away from clinching at least a bronze medal. It’s not 1984, but it’s a step forward.

As Walsh built his native Ireland into an amateur power through the 2008 and 2012 Olympics, he would sometimes look at the Americans with confusion.

“I was wondering: What the hell has gone wrong with USA Boxing?” he said during an interview at the team’s pre-Olympic camp in Colorado Springs. “They weren’t producing. They weren’t a threat anymore.”

So when a friend contacted him in 2014 about becoming the American coach, his first thought was: “Why would I want to go there?” But the potential of rebuilding the American team was too much to resist. He kept thinking about “the sleeping giant” that was USA Boxing. He thought maybe he could wake it up.

Among the first things he did after arriving in Colorado was to paint quotes from American boxing medalists on the doors to serve as inspiration. A photo of Muhammad Ali standing on the podium with his 1960 gold medal was placed on a wall. He showed the fighters video of Leonard. He told them he wanted them to have a vision of being an Olympic champion. He said professional boxing, with all its divisions, has many world champions in each weight class, but the Olympics have only one.

“When you go to fight that country, you fight the best from that country,” he said he told them. “There’s nothing handpicked for you.”

The toughest challenge for Walsh was building trust with the fighters and their coaches. Many of the personal coaches believed USA Boxing’s coaches were trying to steal their fighters. Things got so bad at the 2008 Beijing Olympics that the parents of at least two American boxers shouted instructions from the stands. As Walsh pushed the concept of a U.S. program like those in other countries, he told the personal coaches he wanted them to be partners, that they could work together, talking regularly by phone, creating training plans.

“My ambition is to put your boxer on the top of the world podium and give them back to you,” Walsh said he told the coaches. “… I want to give them the education and development that’s going to stand in a good standing to go professional.”

Slowly, cohesion has come. He sees more young American fighters who want to chase medals, who want their pictures on the wall at the training center, who want to help rebuild USA Boxing. This spring, three fighters who had turned pro — Davis, Troy Isley and Duke Ragan — came back to compete in Tokyo after the canceled Pan American qualifier left the United States with Olympic slots to fill.

Davis, Ragan and super heavyweight Richard Torrez Jr. are the three American men still in contention. If all three can medal, it would end some of the lament about how modern U.S. teams can’t be more like 1976 or 1984.

“Everyone brings up 1984,” Mike McAtee, USA Boxing’s executive director, said before the Olympics. “Well, let’s put it in context.”

Back in 1984, he said, boxing had less competition for top young athletes in the United States. And because the Olympics had a bigger boxing field, each country didn’t have to qualify in international tournaments to fill limited spots at each weight class. Plus, because of the Soviet boycott of the 1984 Games, traditional powers such as Cuba and the Soviet Union were not there. Yes, the United States had great boxers, but it was much easier for them to storm through those Olympics.

He wishes people would stop comparing men’s Olympic boxing today with 1984. Focus on now, he said, on the Americans’ recent success in women’s boxing, with Claressa Shields winning gold in 2012 and 2016 after the sport was added for the London Games, and welterweight Oshae Jones, who already has clinched a medal here in Tokyo.

“How do we bring it back?” McAtee asked. “Win.”

That was what Davis had in mind Saturday as he stood in the corridor under the Kokugikan Arena stands.

Perhaps in part because he was added as what amounts to a wild card in these Olympics, Davis, the light welterweight gold medalist at the 2019 world championships, was placed toward the bottom of the draw here, forced to fight Oumiha, a silver medalist in Rio de Janeiro. It seemed a particularly low seed for someone who is already 3-0 as a professional. But then again, the United States hasn’t had the recent Olympic history that demands better placement.

“That played a part of my excitement, too, when I hit the guy,” Davis said. “They give me these tough opponents early, [and] I feel kind of disrespected, like they’re trying to get me out of the tournament early.”

He smiled.

“Or that’s just how I take it to motivate myself to go into each one of these fights,” he added, before leaving the tunnel at the Olympics that might finally restore the power of American men’s boxing.