The 24-year-old middleweight understands he needs to beat a credible contender like Austin “Ammo” Williams to legitimize himself as a title challenger in the 160-pound division. The Roseland, New Jersey native’s 12-round bout with Williams will be streamed by DAZN and broadcast by TNT from Prudential Center in nearby Newark as a co-feature before former unified heavyweight champ Andy Ruiz opposes Poland’s Damian Knyba in the 12-round main event.

Williams (20-2, 13 KOs) lost his last fight to WBC champ Carlos Adames on March 21, but he has fought a higher level of opposition than Mielnicki (23-1, 13 KOs, 1 NC). The Dominican Republic’s Adames (25-1-1, 18 KOs) and England’s Hamzah Sheeraz (24-0-1, 19 KOs), the WBO super middleweight champ, are the only opponents to beat Williams.

“That’s how I’m looking at it,” Mielnicki told The Ring. “Take care of business Friday night and I’m right in line for a world title.”

Mielnicki is ranked No. 3 by the WBO, No. 7 by the WBA and WBC and No. 9 by the IBF. He is motivated, however, to disprove skeptics that think he hasn’t earned those positions since he moved up from the junior middleweight division late in 2024.

“However fights go you’re gonna hear the talk good and bad,” Mielnicki said. “But I feel like having a name like him on my resume will silence a lotta that. And doing it in the fashion that I believe we’re gonna do it will help that even more.”

Mielnicki made his pro debut at Prudential Center in July 2019, the summer before he began his senior year at West Essex High School.

He overcame an eight-round, majority-decision defeat to James Martin, who upset Mielnicki in April 2021, by winning 12 straight fights. Mielnicki’s 10-round majority draw with undefeated contender Connor Coyle in his middleweight debut 18 months ago was changed to a no-contest because Coyle (23-0, 10 KOs, 1 NC) tested positive for multiple performance-enhancing drugs.

Mielnicki has beaten three undefeated fighters in a row since he faced Coyle – Kamil Gardzielik (20-1, 4 KOs), Samuel Nmomah (21-1, 5 KOs) and Omar Huerta (15-1-1, 13 KOs). His success since June 2025 assured his trainer, Ronnie Shields, and the rest of his team that Mielnicki is prepared for the 30-year-old Williams, a powerful southpaw who was ranked No. 8 in The Ring’s top 10 when he lost a unanimous decision to Adames.

“My team and I, we just feel it’s time now to take that next step,” Mielnicki said. “And to get to that next step, which is world title contention, you have to take fights like this. It’s a perfect opportunity and the perfect fight for me to do that.”

Eddie Hearn added Mielnicki to Matchroom Boxing’s roster two months ago and he didn’t hesitate to take a difficult fight in his debut with another new promoter. Williams (-135), of Royal Palm Beach, Florida, is a slight favorite over Mielnicki (+105), according to DraftKings.

“I try to take every fight like a championship-level fight, but obviously this one I would say is my toughest fight to date,” Mielnicki said. “In my opinion, there’s no hiding that. He’s a tough fighter and he’s been in there with some experienced guys, in a world title fight. But I have a really good team, we’ve put together a really good game plan and we’re ready to go in there and execute it.”