The stakes have been raised in David Nyika's homecoming bout after America's three-time world title contender Tommy Karpency was revealed as the late replacement for Blake Caparello.
Caparello was pulled from the program on Wednesday, just 10 days out from their cruiserweight boxing match-up in Auckland next Saturday, after the Australian veteran failed a drug test.
The experienced southpaw will challenge the findings but his late efforts to clear his name were not accepted by promoters, who scrambled this week to land a suitable replacement for the main event.
Karpency (31-8-1), also a well-travelled southpaw, was confirmed on Thursday, after Nyika and his camp had touched down in Auckland for the Viaduct Events Centre bout.
The 38-year-old Karpency fought for world titles more than a decade ago but has remained active and is fresh off a win over fellow American Joe Jones last month.
The WBO have now joined the IBF in sanctioning the fight, that will be for both organisations' intercontinental cruiserweight belts.
"Securing such a high-quality opponent at short notice is incredibly difficult so we're delighted with this result," promoter David Higgins said.
"It says everything you need to know about Tommy Karpency that he is viewed by both the sanctioning bodies and our broadcast partner as, if anything, a step up from Caparello.
"With that, of course, comes a step up in the challenge for David Nyika. The stakes have just gone up significantly."
Tokyo bronze medallist Nyika (9-0, 8KO) has been based in the rural Queensland town of Gatton with trainer Noel Thornberry since turning professional.
"That's boxing," Nyika said of the late switch.
"My job is to take out whoever my promoters put in front of me and that's what I'm going to do.
"Obviously I have a huge amount of respect for a guy like Tommy who has been in with the best and still continues to perform at an elite level - but it's my time now.
"Tommy Karpency is about to learn that the hard way."
The Duco Events deal is being co-promoted by still-active New Zealand heavyweight star Joseph Parker, who has high hopes for his countryman.
They hope to fight twice more before year's end and push Nyika, who last fought on the Tyson Fury-Oleksandr Usyk undercard in Saudi Arabia in May, towards a world title shot.
"The good news for boxing fans is that they get to see David test himself against one of the best fighters in the world," Parker said.
"It's a huge challenge, but one he will pass."
Thornberry took Queensland cult hero Alex Leapai to a heavyweight world title fight 10 years ago and is now mentoring his son, Alex Jnr, who will have his third professional fight on the undercard.
