— On a night when the toll of a lengthy boxing career was going to be tested in another multimillion-dollar world-title fight, the promise of a limitless future in the sport was also displayed.

Oscar Valdez, a 23-year-old two-time Olympian from Nogales, Mexico, who trains in Santa Fe Springs, won his first belt, the North American Boxing Federation super-featherweight title, with a fourth-round knockout of Florida's Adrian Perez, 33, on Saturday.

"Everything we practiced in the gym we showed in the ring today," Valdez (10-0, 10 knockouts) said inside the MGM Grand Garden Arena ring where 35-year-old Manny Pacquiao was to fight unbeaten Timothy Bradley in the night's main event.

"We worked the head, we worked the body and it was a body shot and right hook to the head that ended it," said Valdez, whose belting of Perez came just as HBO announcers Jim Lampley, Max Kellerman and Roy Jones Jr. were taking their seats.

He winked in their direction at the end, a hopeful acknowledgement they'll be calling his fights someday.

"I'm not going to be satisfied until I get the big, green [World Boxing Council] belt," Valdez said.

Perez (10-5-1) tried to beat Valdez with a tough, forward-charging style, but he was outshined by the kid who slipped punches and damaged Perez with segments like a second-round uppercut-combination.

Fight veterans will like Valdez's attention to punching the body first, as he did in whipping a hard left to the ribs in the third round, followed by two clean body blows capped by a head punch.

"At this point, he's very good, a terrific prospect," said veteran matchmaker Bruce Trampler of Valdez's promotional company, Top Rank. "We have a credo: ability and marketability. We think he has both. When a guy can fight, brings an audience from Mexico, Arizona and California, that's a big fan base.

"Good puncher. This kid's worth paying attention to."

The bilingual Valdez is among a promising group of young fighters in the Top Rank stable, including California light-welterweight Jose Ramirez, Ukrainian featherweight Vasyl Lomachenko and Puerto Rican lightweight Felix Verdejo.

Valdez said he consults with his fellow youngsters about their rise up the boxing ropes, which, for him, will bring a fight six times a year.

Valdez's knockdown, at the 1-minute 23-second mark, brought referee Russell Mora to Perez's side and he counted, "Six, seven, eight," before waving his arms to end it.

Trained by Clemente Medina, the cornerman for former featherweight world champion Abner Mares, Valdez turned pro after losing the bronze-medal fight in the 2012 London Olympics and also failing to medal in Beijing in 2008.

His father, who introduced him to the sport, remains an assistant trainer.

"Being an amateur for so long helped me learn a lot of styles," Valdez said. "I hit pretty hard, and try to be a smart fighter. You always have to work, have discipline. I think every day I go to the gym, 'I'm going to be someone. I'm going to be a champion.' "

Saturday did nothing to alter that optimism.

lance.pugmire@latimes.com

Twitter: @latimespugmire