The New Zealand heavyweight Joseph Parker will fight Ukranian Alexander Dimitrenko in his next bout in Auckland in October.
Dimitrenko will have a nine-centimetre height advantage, and an 18 centimetre reach advantage when they step into the ring in Manukau on October 1st.
Parker is the current IBF mandatory challenger, with a world title fight against Anthony Joshua to be held before the end of the year.
However if Parker is beaten by Dimitrenko he will lose his mandatory challenger position.
The 12-round bout will take place at the Vodafone Events Centre in Manukau, the same venue where Parker beat Carlos Takam to secure the IBF number one mandatory position in May.
Ukrainian Dimitrenko has an impressive 38-2 record, with 24 of those wins coming by way of knockout.
Dimitrenko is a former European Heavyweight Champion and is bigger in size than current IBF World Champion Joshua.
The Ukrainian is on a six-fight winning streak and, by taking on this challenge, Parker risks his guaranteed world title shot in 67 days time.
"Dimitrenko is a guy who former World Champion, Shannon Briggs went out of his way to avoid earlier this year because of the risk," said Duco Events promoter, Dean Lonergan.
"Even casual boxing fans know that all Eastern Europeans in the heavyweight division know how to fight."
The 33-year-old Dimitri is 6'7" or 2.01m tall.