Eight fighters have been drawn against each other with the elimination contest seeing a winner declared on the night.
Peckham-born Osaze, who has won all six of his professional bouts, faces Tey Lynn-Jones in his quarter-final.
The 25-year-old South Londoner is a youth pastor at God’s Vineyard Ministries in Nottingham while also forging a career as a prizefighter.
Osaze said: “Growing up, I had some anger issues – fighting in school, a few red cards playing sports. I wouldn’t say I was especially violent but I certainly had a short fuse.
“So I started attending a boxing gym in Charlton, in an attempt to keep out of trouble. Gradually, my hobby became my passion, then my lifestyle. Boxing changed my life, helped me deal with my aggression, instilled self-discipline.
“I grew up a Catholic and weekends were always spent in church. Once I got to uni, living on my own, I wavered a bit before rededicated my life to the Lord in my final year. Today, as a pastor I give sermons and lead prayers at a Pentecostal Church, and I mentor young people.
“My faith in God keeps me grounded and reassures me that nothing I face can break me. There’s a big misconception that just because you go to church, life is plain sailing. It’s not. Something good comes out of each challenge which makes us stronger.
“My faith certainly helps with the mental side of the sport. Above all, it gives me peace and serenity and a happy boxer is a dangerous boxer.
“Before fights, I pray that neither my opponent or myself sustain any life-threatening injuries but there’s no conflict. Boxing’s like a martial art, hit and don’t get hit. It’s competition. God understands I’m just doing my job.”
Osaze holds a degree in business management and a masters in sport psychology.
He said: “It’s my ambition to go all the way, to be world champion. I don’t want money, I want to achieve. In addition to Ultimate Boxxer, I’d like a title this year.
“On May 10, fans are going to witness the very best version of me, in the best possible physical condition.
“The three-round UB format will suit me because I always start fast. I’ve a counter aggressive style. I’m adaptable, I can go front foot or back. I pose different challenges to every opponent and do whatever is necessary to win.”
Osaze is one of five unbeaten fighters in the tournament.
“I love the concept of all the best young prospects in a category coming together because it forces match-ups that wouldn’t be made outside such a tournament,” he said.
“I’m not into all the razzamatazz of unbeaten records. So many are padded. If you want to get somewhere in the rankings, you have to take risks, test yourself.
“This is ‘nothing to lose, everything to gain’. It’s a perfect launch pad that can provide great exposure.”
UB III is exclusively live on BT Sports and BT Sports’ YouTube channel – available to watch for free.