Jose Ramirez and Josh Taylor have worked for decades to reach this moment. On Saturday in Las Vegas, one of the two undefeated and unified champions will add another "u" word to his résumé: undisputed.

Ramirez and Taylor will fight for all four major junior welterweight titles at Virgin Hotels in Las Vegas (ESPN and ESPN+, 8 p.m. ET, with prelims on ESPN+ starting at 4:45 p.m. ET). Both fighters are 2012 Olympians who turned their failure to win gold into professional careers in which they now own gold of a different kind, in the form of two belts apiece wrapped around their waists.

Taylor (17-0) earned his path to this fight through a talent-rich World Boxing Super Series (WBSS) junior welterweight tournament, which included Regis Prograis, Ivan Baranchyk and Ryan Martin. Ramirez (26-0) last made a statement with a knockout win over Maurice Hooker to unify two of the four belts.

Their destination of this fight is the same, but reaching it included challenges, disappointments and ultimately glory. Both fighters told ESPN their story and reflected on what it means to even be in the ring with stakes so high this weekend.

Editor's note: Content has been edited for clarity and brevity.

Early days and the Olympics

Taylor: The Olympics were a real disappointment. I had moved up and left 60 kilograms (132 pounds) behind, as I was really struggling to do the weight. But I just missed out on qualifying for Team GB's spot at 64kg (141 pounds) at the London 2012 Olympics, and then Rob McCracken, the Team GB coach, told me nobody had qualified for 60kg -- did I want to go for it? I remember thinking, "I'm never going to make that weight." I made it, but I was weight-drained.

I was the first person from Scotland to qualify for the Olympics for such a long time, and I beat Robson Conceicao of Brazil in my first bout. But then I lost to Domenico Valentino of Italy in my next one, on the daft scoring system. I felt really pissed off I had come up short, I really felt I could win a medal.

I was always going to continue as an amateur after the 2012 Olympics, because I hate losing at anything. I'm so competitive in anything I do, so I was always going to carry on after it. I won a gold medal at the Commonwealth Games in 2014 and it was a really proud moment for me -- to do it in front of my home fans in Glasgow.

After that, it was the perfect time for me to strike a pro deal.

Ramirez: The U.S. Olympic team from 2012, most of us became world champions -- Jamel Herring, Errol Spence Jr., Rau'Shee Warren, Claressa Shields, Marcus Browne (interim titlist), Joseph Diaz Jr. -- but we didn't win a medal on the men's team. I was only 19 and had only started boxing internationally in 2011 -- and we also lacked experience of fighting with the scoring system.

My professional career started pretty soon after the Olympics. I signed a very good deal with Top Rank and my pro debut was on the same bill as Manny Pacquiao-Juan Manuel Marquez -- the fourth time they met each other, when Marquez knocked out Pacquiao in December 2012. I was boxing three or four times a year from then on, getting experience, and I really moved quickly, facing undefeated fighters and fighters who had not been stopped before.


Breakout moment

Taylor: I won my first title in my seventh fight in October 2016, the Commonwealth title, against a good pro in Dave Ryan. It was at the Meadowbank Sports Centre in my home city of Edinburgh, and that was special. That was the place which helped get me into boxing in the first place.

Meadowbank was the first boxing club I went to -- we used to box in a gym under the stadium, and it's where I first got inspired by training and sparring with Alex Arthur. My mum was a receptionist at Meadowbank and she knew Alex, who used to train there, and one day I went to train with him.

He was great with me because I was only learning at the time. When I fought Ryan, there were [3,000] or 4,000 there. I came out to Black Box's "Ride on Time" and the place was absolutely jumping. I put on a good performance against a good domestic fighter, and it's a great memory. I took him apart, won in the fifth round and that's when people started to take notice of me.

Ramirez: When the Mike Reed fight came in November 2017, he was undefeated and he believed he was the better fighter. I remembered seeing him from the amateurs -- he was a junior welterweight and I was a lightweight back then -- and I remember him being slick, a good boxer. But I knew I was a better fighter than he believed I was, and also I was a lot bigger than when I was in the amateurs.

I scored a second-round knockout, and that really brought me a lot of confidence, that I could believe I was on a different level to some of these other fighters who were undefeated after 20 fights or so. After the Mike Reed fight, I knew I was ready for a world title fight.


First major title

Taylor: The World Boxing Super Series was a no-brainer for me to enter. It offered three fights, the chance to win two world titles and we all got paid well for it. I went into the Viktor Postol fight in 2018 (a unanimous decision victory for Taylor) knowing that the WBSS was coming around, but we took the Postol fight trying to get a shot at Ramirez for the WBC title back then. So, I had a lot hanging in the balance going into that Postol fight, no matter which way things turned.

I beat Ryan Martin by TKO in November 2018 in my first fight in the WBSS, and it was a great display. He was known as "blue chip" and a lot of people rated him, but I blew him away with my boxing skills. He went into his shell after I started outboxing him.

Then I beat IBF world champion Ivan Baranchyk in the WBSS semifinal by unanimous points in May 2019, but looking back, I could have made it easier than it was. I thought I was ahead halfway through, so I started to move around the ring a bit and I noticed the crowd suddenly went silent, like they were worried. It made me try to take the fight to him. I could have done without getting hit so much.

It was a brilliant feeling to win my first world title, but I wasn't surprised or overly excited by it. I just thought, "That's my goal done, what's next?" and set myself new goals. It was a short-lived celebration, because I already had a fight lined up, the WBSS final and unification fight with Regis Prograis, the WBA champion. It wasn't long after the Baranchyk fight that I was back in the gym preparing for Prograis.

Ramirez: I've been boxing since I was 8 years old. I had about 200 amateur fights and along the way I made so many sacrifices over the years and put so much time into the sport. I always feared coming up short and not becoming a world champion, but the sport paid me back for everything I had worked for and all the dedication I had given to the sport in that fight against Amir Imam.

That small, little worry motivated me to push myself really, really hard, and helped me to remember why I'm doing this and how I was really close to achieving something that will both change my life financially and my career as a fighter.

Imam had beaten guys like Yordenis Ugas, who's now a world welterweight champion, and he had good, good power. He was lanky and strong, with a good right hand. He had only lost to Adrian Granados at that point, and according to his team, that was because he had a cold the week of the fight. He was a good boxer, but I was able to break him down and become a world champion when I won the WBC world super lightweight belt in March 2018.

It was one of the most amazing feelings of my life, to know I had accomplished my dream since I was a little boy. To hold the WBC belt, the green and gold belt, that was the belt I had dreamed of since I was a kid.


A second piece of gold

In 2018, Taylor joined the World Boxing Super Series junior welterweight tournament, a group that featured eight fighters (Taylor, Regis Prograis, Kiryl Relikh, Ivan Baranchyk, Terry Flanagan, Ryan Martin, Anthony Yigit and Eduard Troyanovsky) in a single-elimination bracket, vying for the Muhammad Ali Trophy.

Taylor: Prograis was the WBA champion and he got more publicity than me ahead of our fight in October 2019, even though he was from America and the fight took place at the 02 Arena in London. There were more cameras around him in the lead-up to that fight, which felt bigger than any of my others.

I thought I won the first two rounds, then I got caught a couple of times by his head because of a clash of styles, so I changed it up a bit and started to box at a slower pace. He came into it and my eye closed completely, so I had to box the last three rounds with one eye -- but I still won the fight. Tactics went out of the window because I was blind for those three rounds; it was down to heart and determination. It was a combination of work rate and a variety of punches that won it for me overall.

Prograis was very good, very strong and had good timing, but I knew I could get to him inside. I don't think he expected me to be able to switch it up so easily.

I believe we saw the best of me in that fight. Prograis was a great champion, but the best man won.

It felt amazing to be a unified world champ in only 16 fights but after the Prograis win, all the talk quickly turned to Ramirez and my focus was on becoming the only champion in the division and winning the other two belts. That's not been done in Scotland since Ken Buchanan at lightweight in 1971 -- he was the last undisputed champion from Scotland and he comes from Edinburgh as well.

Ramirez: The Maurice Hooker fight in July 2019 was probably my best performance. He was an undefeated world champion, and I proved what kind of fighter I am in the way I was able to capitalize on all the opportunities I saw to stop him in the sixth round. I was happy with it because I was able to become a unified world champion, and also because of fans... they become believers when you beat an undefeated world champion like Hooker.

There haven't been moments in my career where I have looked like I would lose, where people would say "Jose got saved by the bell in that round," or there were concerns. And any doubts there might have been were erased. The Hooker fight might have surprised a lot of people, but it didn't surprise me.


Fighting to be undisputed

Taylor: It was a dream years ago to be undisputed champion -- an unrealistic dream. Because when you think about unified champions, they were the superstars of the sport -- people like Oscar De La Hoya, Floyd Mayweather, Manny Pacquiao and big names like Canelo Alvarez. When I thought about me doing it, I thought it was a bit far-fetched for a wee guy from Prestonpans, Scotland, reaching that level. But one thing has progressed to another, and here we are.

Did I think I fight like this particular would ever come my way? Probably not. It's happened so quickly. If it wasn't for the WBSS, I might still be waiting on Ramirez -- it might have been like Mayweather-Pacquiao and just dragged on for years.

Undisputed world title fights in Las Vegas are rare, special. I'm really lucky and privileged to be in this position, to land a fight of this magnitude. But I have worked my backside off to get to this position, I didn't get here by luck, and I will do my hardest to make sure I make the most of the opportunity on May 22.

Ramirez: My fights have gotten bigger, my paydays went up. I was able to make investments outside of the sport and really take care of my family with some privileges that we never had before.

We come from very humble beginnings with very few opportunities. To know I could give my family and my kids a better life was a beautiful feeling. Once I became a world champion, I felt a big weight on my shoulders had come off and my confidence just kind of grew. I wanted more -- more big fights, more glory.

This fight will be different than the Postol one -- it's a big fight for boxing, and it's an honor to be involved in such a big fight.