LAS VEGAS — Jeison Rosario lost his will to live a few months after he lost his desire to box.

By March 2023, the former unified junior middleweight champion became so depressed that the thought of suicide consumed him every day. That’s how little life meant to Rosario, who shocked the boxing world five years ago when he upset 30-to-1 favorite Julian Williams by fifth-round technical knockout to capture the WBA, IBO and IBF titles in Williams’ hometown of Philadelphia.

“It was so bad,” Rosario says, “that I woke up every morning thinking about taking my own life.”

Rosario had already retired at that point, hanging up his gloves at age 27 following a devastating fifth-round knockout loss to Brian Mendoza in late 2022. Mendoza was the third fighter to knock out Rosario over a 25-month span, which left Rosario hopeless regarding rejuvenating his career. The one-time 154-pound champion promptly retired in his locker room after Mendoza demolished him, though Rosario's youth left fans and reporters skeptical about his commitment to ending his prizefighting career.

Little did they know that the consequences of those losses, abandonment and the fear of not knowing how he would provide for his three children back in the Dominican Republic, ravaged Rosario’s psyche.

“It was more than boxing,” Rosario recalls. “I felt miserable overall. My self-esteem was shot, very low. I really felt like living made no sense overall. I felt that life had lost its meaning.”

Rosario credits his wife of two and a half years, Thaina, for helping him out of what, at times, was a bottomless depression. Thaina Rosario strongly encouraged her husband to restore his connection to God, which he believes led him to a new trainer, respected Las Vegas-based cornerman Bob Santos.

“Absolutely everyone left my side,” Rosario says. “And when I say everyone, I [mean] everybody. The only one that stayed by me, and never left my side, was my wife. She was the one who stayed with me through thick and thin, held my hand and led me through the darkness and into where I am now. I don’t know what I would do without her.”

A reinvigorated Rosario (23-4-2, 17 KOs) moved from New York to Las Vegas this past spring to begin training at Santos’ gym. His performance in his August comeback fight — a 10-round draw with fellow former unified 154-pound champ Jarrett Hurd — helped Rosario secure a more meaningful bout Saturday night in Las Vegas, where the refocused fighter nicknamed “Banana” will attempt to pull off another huge upset.

Rosario, 29, takes on top prospect Jesus Ramos, a 23-year-old southpaw who has his own championship aspirations within the loaded junior middleweight division. Ramos (21-1, 17 KOs), of Casa Grande, Arizona, is listed by BetMGM as a 25-to-1 favorite to defeat Rosario in the pay-per-view opener on the stacked David Benavidez vs. David Morrell Jr. undercard at T-Mobile Arena (8 p.m. ET; Prime Video, $79.95).

“I left my depression behind in New York,” Rosario says. “I came to Las Vegas with a positive mindset and that’s where I am now, in Las Vegas, living my best life.”

Ramos remembers being inspired when he watched Rosario win the junior middleweight belts from Williams. Rosario’s reign lasted only eight months before Jermell Charlo knocked him out in the eighth round of Rosario’s next fight, a 12-round title unification clash in September 2020.

The respectful Ramos realizes Rosario still possesses plenty of power. He also understands he is heavily favored to win Saturday's 10-rounder for a reason.

“I thought he was a lot older, and he’s only 29,” Ramos says. “So, he’s fairly young. But, I mean, sometimes that’s the way it goes. He had tough fight after tough fight. And I hate to use this word, but sometimes fighters get shot. It happens. I’ve seen it time and time again. They don’t react the same and it happens when you’re fighting these tough, tough fights, and sometimes getting knocked out like that is tough. But it was sad, man, because I was a fan of Jeison Rosario.

“I remember when he fought [Nathaniel] Gallimore [in April 2017] and Gallimore was signed to the same management company as me. We saw that fight and he lost [by knockout]. Then he bounced back. I watched his career and I was really excited when he beat Julian Williams. I liked his style. I liked to study that fight. It seemed like he had a really good style going into that fight with Julian Williams.”

Hurd also attempted to resurrect his career when he entered the ring as a slight favorite to beat Rosario five months ago in Plant City, Florida. Rosario beat him 96-94 on the scorecard of judge Mike Ross, but Hurd won 96-94 according to Joann Richard and James O’Connor had it even, 95-95.

“I gave the edge to Hurd, but I thought [Rosario] did really good,” Ramos recalls. “He did look a little past his prime, a little slower, not the same Rosario that perhaps we saw against Julian Williams, even Brian Mendoza. I think when he fought Brian Mendoza, he was still a little sharper. With Hurd, he looked past his prime, but I think still he looked good. He’s still a threat. You can tell he still has the punching power, so there’s a lot to look out for in the fight versus Rosario.”

However he fares versus Ramos, Rosario realizes he has won a much more brutal battle with his own demons. He hopes when other dejected boxers and athletes read his story, that they’ll become motivated to figuratively fight their way out of similar challenging circumstances.

“This kind of story, one of overcoming adversity, is one people should hear,” Rosario said. “I’m glad I can tell my story in a way where I can inspire people, and also show that boxing is about more than just the gloves you put on your fists and how strong you can be. It’s also about overcoming adversity in the toughest times of your life, and then coming out the other side successfully.”