Promoted by Oscar De La Hoya, Larios began his career at 17 and dropped early losses to Israel Vázquez by KO in the 1st round and Agapito Sánchez by TKO in the 5th prior to hitting his stride as he accumulated a record of 39-2 before his first world title.
Larios went on to defend his title 7 times (along with 3 non-title fights), including a victory over Nedal Hussein and two wins over fan favorite Wayne McCullough.
In July 2006, Larios moved up to Super Featherweight to take on then three-division world champion Manny Pacquiao, a Filipino boxer highly capable of besting opponents by KO.
After the fight with Linares, Larios was diagnosed with a minor subdural hematoma, bleeding of the brain, putting any hopes of a future boxing career in jeopardy.
[1] On August 2, 2008, in Zapopan, Jalisco, Larios made his first defense of the WBC interim featherweight title, defeating Marlon Aguilar by seventh-round knockout.