Eddie Hearn has matched the unbeaten middleweight with his toughest opponent yet just days after signing him to Matchroom Boxing
Vito Mielnicki Jr. won’t receive a gentle introduction to Matchroom Boxing. Just days after signing with Eddie Hearn’s promotional company, the unbeaten middleweight has landed a September 4 showdown with Austin “Ammo” Williams in the biggest test of his career.
Mielnicki (23-1, 13 KOs) has won 15 straight fights since suffering the lone defeat of his career to James Martin in 2021. He also has a no-contest against Connor Coyle after their majority draw in February 2025 was overturned when Coyle tested positive for a performance-enhancing drug.
While Mielnicki has steadily climbed the rankings, reaching #2 with the WBO and #7 with both the IBF and WBC, questions remain about how he will do against proven world-level opposition. Much of his career was spent developing on Top Rank cards against carefully selected opposition, making Williams a considerable step up in class.
Williams (20-2, 13 KOs) brings far more experience against elite competition. His only defeats have come against current WBC middleweight champion Carlos Adames and current WBO super middleweight champion Hamzah Sheeraz, two of the division’s best fighters. The 30-year-old rebounded from the Sheeraz loss before dropping a competitive unanimous decision to Adames in March.
Stylistically, Williams presents a difficult assignment. The southpaw combines heavy hands with relentless pressure and has consistently performed well against opponents looking to establish themselves at contender level. It is the type of fight that should quickly reveal whether Mielnicki is ready to compete with the division’s leading names.
Matchroom could have given Mielnicki a confidence-building debut in front of his hometown fans. Instead, the promotion has thrown him in with one of the toughest tests available outside the world champions. It’s the type of fight that should answer plenty of questions about just how far Mielnicki can go at middleweight.
The September 4 card is expected to be one of Matchroom’s biggest U.S. events of the year, with Shakur Stevenson widely linked to the main event in Newark, though the full lineup has yet to be officially announced. It’s a chance for Mielnick to prove he belongs among the division’s leading contenders. For Williams, it’s an opportunity to spoil the hometown celebration and remind everyone he remains a dangerous player in the middleweight division.