He made his U.S. boxing debut in 2011, securing a victory over Hector Munoz at the MGM Grand.
Kamegai fought Johan Pérez for the WBA International welterweight title, and was dealt his first professional defeat via unanimous decision.
In this match Kamegai was able to damage Soto Karass early with a left body blow from the side.
Kamegai landed flush shots for the remainder of the match until Soto Karass retired in the corner, which was labeled as a TKO.
[8] On May 24, it was announced a deal was made for a fight between Cotto and Kamegai to take place on August 26, 2017 at the StubHub Center in Carson, California live on HBO.