The 24-year-old has compiled an impressive record, but this is the first time he’ll enter the ring against an opponent with proven world-level credentials. It’s the type of fight that should reveal exactly where Mielnicki stands among the division’s contenders.

First Real Test

Mielnicki enters the bout with a record of 23-1 with 13 knockouts. He has won 15 straight fights since suffering a majority decision defeat to James Martin in 2021. While he sits No. 2 with the WBO and No. 7 with both the IBF and WBC, he has yet to score a defining victory over an established contender. Much of his career has been spent progressing through a measured schedule on Premier Boxing Champions and Top Rank cards.

Williams represents the toughest opponent of Mielnicki’s career.

The 30-year-old southpaw owns a 20-2 record with 13 knockouts. His only defeats came against Hamzah Sheeraz, who stopped him in 2024, and current WBC middleweight champion Carlos Adames, who earned a unanimous decision over him in March.

Williams has built a reputation as an aggressive southpaw with legitimate power. He has already tested himself against elite opposition and won’t be intimidated by fighting in Mielnicki’s backyard.

No Easy Welcome Home

Matchroom had every opportunity to give Mielnicki a manageable hometown debut. Instead, it matched him with one of the most experienced contenders outside the championship picture.

The September 4 card is shaping up to be a major night for East Coast boxing, with Newark’s Shakur Stevenson heavily linked to the main event, although it has yet to be officially announced.

Mielnicki has spent the past five years climbing the rankings. On September 4, he’ll find out if he’s ready for the fighters waiting at the top. Williams, meanwhile, has the chance to remind the division that he’s far more than a measuring stick for the sport’s next generation.