Lopez began boxing before he was 10 years old. He has 70 amateur bouts. The 18-year-old Lopez made his professional debut in Las Vegas as a 135lbs on Feb. 8, 2003, stopping the favored Allen Litzau just 53 seconds into the 1st RD.
Josesito Lopez scored a seventh round KO over previously unbeaten jr welterweight Mike Dallas Jr (17-1-1, 7 KOs) in a clash for the NABF belt. Lopez overcame vertical cut from an unintentional headbutt and steadily roughed up and broke down Dallas, sending him to the deck as referee Raul Caiz Jr. waved it off. Time was 1:47.