 Two months later, he defeated Araik Sachbazjan when Sachbazjan retired before the beginning of round four.After winning his first four fights in Germany, Gamboa made his United States debut on 30 October 2007, at the Seminole Hard Rock Hotel and Casino in Hollywood, Florida, against Adailton De Jesus, who was dropped to the canvas halfway through the first round.A Gamboa slip in the fourth round was ruled a knockdown by the referee.