Since 2014, there have only been two in women's boxing: welterweight Cecelia Braekhus, and more recently middleweight Claressa Shields.
WBC female lightweight champion Belgian Delfine Persoon (43-1) will face Irish sensation Katie Taylor (13-0), who holds all three other titles - WBA, IBF and WBO - in a supreme unification for all four world titles and the pinnacle that is The Ring Magazine belt this Saturday, June 1 at Madison Square Garden in NY.
On June 1, we have one of the biggest fights in women's boxing history; Katie Taylor vs Delfine Persoon for the undisputed lightweight title! "I know what to expect", she told Sky Sports.
"I love to perform on the big stage". I'm always respectful regardless of what my opponent does.
"I've watched clips of her and she's very tall and awkward, she punches non-stop for the ten rounds and I think it's going to be a very physical fight".
Taylor said: "This fight is going to be the toughest of my career so far, Delfine is a fantastic champion". It's an emotional moment, indicative of how important Taylor's Catholic religion is to her - even more so than boxing.
For me it's very exciting. I can't wait. I want to pull out the performance of a lifetime.
If Taylor, a 2012 Olympic gold medalist, tops Persoon, she hopes to defend each of her four lightweight titles moving forward.
Persoon's height advantage was clear to see and both fighters held a stare for about 15 seconds as their names and titles were read aloud.
"She will win the fourth title, she is the best there is about", he adds.
Meanwhile undaunted Taylor is undefeated in 13 matches.
Persoon (34), who boasts a record of 43 wins and just one defeat, believes beating Taylor (32) could put boxing on the map in her country.
At the weigh-in alongside Delfine Persoon.
Katie Taylor's promoter believes she has denied herself the chance to become one of the world's most famous female athletes to instead become one of its most successful.
"Now if you look at any club it's packed with female boxers and they all have a dream of becoming an Olympic Champion or a world champion".
"The only time we were asked to fight outside Belgium was in 2015 when she defended her title in Switzerland".
Persoon will earn the biggest purse of his career - probably in excess of $150,000.
"It's a huge challenge but the one that I've wanted". I'm ready to make history.
Katie Taylor can cement her place as arguably the greatest Irish sportsperson of all-time, when she steps into the ring at Madison Square Garden in NY on Saturday. She responded with a bow before the pair shook hands and Persoon bowed again.