Gilberto Ramirez, Oscar Valdez to fight on undercard of Terence Crawford-Viktor Postol

Super middleweight titlist Gilberto "Zurdo" Ramirez and featherweight contender Oscar Valdez, two of the most talented young boxers in Top Rank promoter Bob Arum's stable, will fight in world title bouts on the undercard of the Terence Crawford-Viktor Postol junior welterweight title unification fight this summer.

Arum on Tuesday formally announced at a news conference in Los Angeles that they will fight on the card July 23 (HBO PPV, 9 p.m. ET) at the MGM Grand in Las Vegas, where Ramirez won his 168-pound world title by shutout decision against longtime division stalwart Arthur Abraham on April 9 on the Manny Pacquiao-Timothy Bradley Jr. HBO PPV undercard.

The 24-year-old Ramirez (34-0, 24 KOs), of Mexico, will be making his first title defense against Germany's Dominik Britsch (32-2-1, 11 KOs), 28, in the co-feature.

"I am very excited to be making my first world title defense. I am working hard to make it a successful defense as I plan to be a world champion for a long time," Ramirez said. "Dominik is a tough challenger, very strong. I don't know a lot about him personally, but I will train hard as always. It feels great being on another HBO PPV event. One day I want to be in the main event of a pay-per-view. That goal motivates me to do my best."

Britsch has won four fights in a row since an eight-round decision loss in 2014, but he is taking a big step up in competition.

"I am very happy to be fighting the No. 1 super middleweight -- world champion Gilberto Ramirez," Britsch said. "My slogan is, 'Only those who dare to lose can win.' Gilberto, I am ready for you."

Valdez (19-0, 17 KOs), 25, a two-time Mexican Olympian, will take on Argentina's Matias Rueda (26-0, 23 KOs) for a vacant interim featherweight title. The belt is currently held by Vasyl Lomachenko, but Lomachenko is moving up in weight to challenge junior lightweight world titleholder Roman "Rocky" Martinez on June 11. If Lomachenko wins, he is expected to remain at junior lightweight and vacate the featherweight belt, which would allow the Valdez-Rueda winner to fill the vacancy.

"I really believe that, looking at my past few fights, I have earned the opportunity to fight for a world championship," Valdez said. "Now is the time to take advantage of this opportunity."

Valdez is coming off the biggest win of his career, a devastating fourth-round knockout of former featherweight world titleholder Evgeny Gradovich on the Pacquiao-Bradley III undercard.

Rueda, 28, has scored knockouts in his last 10 fights, although he has yet to face a recognizable opponent.

"Although this will be my second fight in the U.S. and many people might think I am not the favorite, I will surprise lots of fans," Rueda said. "I respect my opponent, but I am going to Las Vegas determined and with only one thing on my mind -- winning the belt and bringing it back to Argentina with me. You can all be sure of that. My opponent is going to lose. I respect him. He is a very good fighter, but he will lose."

Arum also announced that former interim junior welterweight titlist Jose Benavidez Jr. (24-0, 16 KOs), 24, of Phoenix, and Francisco "Chia" Santana (24-4-1, 12 KOs) will square off in a scheduled 10-round welterweight bout that will open the pay-per-view telecast.

"This fight is very important because I want to show everyone that I am ready to beat world-class fighters in the welterweight division," said Benavidez, who vacated his interim junior welterweight belt late last year because he could no longer make 140 pounds. "I know Santana is a good fighter, but I have what it takes to outclass and beat him on July 23. I have been training hard and am more than ready to show what I bring to the table on fight night and prove I belong."

Santana, 30, of Santa Barbara, California, has won two fights in a row since a 10-round decision loss to Sadam Ali in April 2015.

"I feel extremely blessed to be fighting against Benavidez on HBO PPV," Santana said. "He is a talented fighter, but I am ready to rise to the occasion and prove to the world that I am an elite fighter and a future world champion. I view this fight as getting me one step closer to a world title shot. On the night we get into the ring, I will live up to my motto, 'Train, fight, win,' one fight at a time."