Katie Taylor feels unifying the lightweight division would be a better achievement that winning Olympic gold in London 2012 as she prepares for the most important bout of her professional career on Saturday night.
The Bray boxer takes on Delfine Persoon in Madison Square Garden as a support fight to Anthony Joshua’s heavyweight title defence against Andy Ruiz Junior.
Taylor has won the WBO, WBA and IBF crowns so far and Persoon, the WBC champion, stands in the way of conquering the 60kg division.
She would become the first Irish person to win all four belts at any weight class.
She told Sky Sports: "This is a fight I have always wanted.
"To be fighting for the undisputed title in Madison Square Garden is absolutely phenomenal really.
"This journey has been incredible over the last few years and hopefully I will perform well on June 1.
"I cannot wait to write my name in the history books. Ever since I did turn pro, I wanted to become the undisputed champion, I wanted to make history in this sport and I am so close to it now.
"Delfine Persoon is a fantastic champion.
"She has been a champion for numerous years now - a long-reigning champion. I think she has had 43 wins and one loss so she is an outstanding champion.
"That is why I have prepared so hard for this fight. I am expecting my toughest fight to date but I am ready for this challenge and I am ready to perform brilliantly on Saturday night.
"This is the pinnacle of the sport really - to become the undisputed champion of the world is the pinnacle of boxing.
"This would be the biggest night of my career so far. The Olympics in 2012 was absolutely outstanding but I think this night would even pass that out. This is definitely the biggest night of career and I can't wait for it."
Persoon believes it will be a showpiece occasion for women’s boxing.
"I am very excited. The winner of this fight is the undisputed lightweight champion and gets the four belts as well as the Ring Magazine title so it is a big fight," Persoon said.
"I think for both fighters it is going to be the hardest fight. We have two different styles so I think it is going to be a hard fight and a good fight for women's boxing."
Follow a live blog on Katie Taylor vs Delfine Persoon from 1.30am on Sunday morning