George Kambosos Jr. just wouldn’t have felt right about boxing an unknown underdog in his first fight as a unified lightweight champion.

Kambosos thus insisted on facing a top 135-pound opponent in his triumphant return to Australia on June 5. Once Vasiliy Lomachenko withdrew from their fight at Marvel Stadium in Melbourne to remain committed to his native Ukraine’s war with Russia, Kambosos pushed promoter Lou DiBella to land Devin Haney as Lomachenko’s replacement.

Securing Haney took some negotiating, but their full lightweight title unification fight was announced at a press conference Friday morning at Marvel Stadium (Thursday night in the United States).

Sydney’s Kambosos, 28, will defend the IBF, WBA and WBO belts he won from Brooklyn’s Teofimo Lopez, who surprisingly lost a 12-round split decision to Kambosos on November 27 at Madison Square Garden’s Hulu Theater in New York.

“It was a fantastic win, a great win, against all odds, 13-1 underdog,” Kambosos said during the press conference. “But I knew what I was gonna do that night. I never changed. I said all along, from day [one], I will be world champion, especially on that night. But that’s a thing of the past now. I’m never content. I’m always striving for more and more. That’s why I chased the biggest names.

“There was only two names I ever asked for, for this stadium fight, return fight. I could’ve fought anybody. Any person I could’ve picked. But I went for one of the best names, Lomachenko, Devin Haney. Unfortunately, Lomachenko’s not available. Beautiful. Devin Haney, step up. Now we’ll take your belt.”

Las Vegas’ Haney holds the WBC world lightweight title, the only legitimate belt Kambosos didn’t win from the heavily favored Lopez (16-1, 12 KOs). Short of a draw or a no-contest, Kambosos (20-0, 10 KOs) or Haney (27-0, 15 KOs) will emerge from their fight as boxing’s first fully unified lightweight champion of the sport’s four-belt era.

Had Haney declined this lucrative offer to box Kambosos in what will be an ESPN main event in the United States, Kambosos would’ve been forced to take the type of homecoming bout he pushed to avoid. That’s among the reasons Kambosos is happy Haney accepted a multi-fight deal with Bob Arum’s Top Rank Inc., DiBella Entertainment and ESPN.

“I’m a Spartan warrior,” Kambosos said. “I want the best fights. I want the best warriors to keep showing the world what I’m about. Correct – I could’ve fought anybody. But could I do that on my homecoming fight, my return fight, this beautiful stadium? Give you guys an easy fight and [have people] leave with a sour taste in your mouth? Never. I can’t look at myself in the mirror. I said, ‘I’ll fight the best guys. I’ll bring this fight back to Australia.’ And that I did.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.