Rosenblatt became a professional boxer in 1992, at the age of 20. He made $500 for his first fight, which was in
Pikesville, Maryland. His only professional loss came when 2-time former champion
Vinny Pazienza knocked him out in the 4th round during a 1996 fight. Following the bout Pazienza was fined $5,000 and suspended for 90 days by New Jersey boxing commissioner
Larry Hazzard for punching referee Tony Orlando who had stepped in to stop the fight. Rosenblatt later beat Pazienza in the 1999 rematch in a split decision, winning the vacant
International Boxing Organization Super Middleweight Title. Rosenblatt broke his hand in his victory over Glenwood Brown in January 1997 and needed over a year to recover. On September 25, 1998, he defeated former 3-time WBC
super welterweight champion "Terrible" Terry Norris in a unanimous 12-round decision, to capture the International Boxing Association World Middleweight Title. He defeated Will "Kid Fire" McIntyre, 36–4–1, in October 2000. Several injuries, including a torn right shoulder
rotator cuff, a separated left shoulder and
torn labrum, and a hand fracture, led to a 20-month hiatus. His next fight was also his last: in a technical draw against Juan Carlos Viloria on June 28, 2002, Rosenblatt was again injured. He announced his retirement in August 2003 with a record of 37–1–2 (23). ==Career after boxing==