Jose Luis Castillo, born on December 14, 1973, in Empalme, Sonora, Mexico, is a former professional boxer who left an indelible mark on the lightweight division during his illustrious career. Widely considered one of the best lightweights of his era, Castillo's tenacity, power, and relentless pressure made him a formidable opponent for anyone who stepped into the ring with him.

Castillo's professional journey began in 1990, and he quickly established himself as a force to be reckoned with. His breakthrough moment came in 2000 when he challenged Stevie Johnston for the WBC lightweight title. Castillo scored a stunning upset despite being a heavy underdog, defeating Johnston by a majority decision and earning The Ring Magazine's Upset of the Year award.

Castillo, as the new WBC lightweight champion, defended his title against top contenders like César Bazán and Stevie Johnston in a rematch. However, his two fights against the undefeated American junior lightweight champion Floyd Mayweather Jr. truly cemented Castillo's place in boxing history.

In their first encounter in 2002, Castillo gave Mayweather the most brutal fight of his career up to that point. Although Mayweather emerged victorious by unanimous decision, the fight was much closer than the scorecards suggested. Castillo's relentless pressure and body punching had Mayweather on the ropes, and many observers felt that Castillo had done enough to win.

The controversial nature of the decision led to a rematch later that year, which Mayweather won more convincingly. Despite the loss, Castillo's performance in these two fights earned him the respect of boxing fans worldwide, as he had pushed one of the sport's pound-for-pound best to his limits.

Castillo defeated Juan Lazcano in 2004 to regain the WBC lightweight title, along with The Ring Magazine and lineal titles. He successfully defended his titles against Joel Casamayor and Julio Díaz before engaging in his most memorable fight against Diego Corrales in 2005.

The first Castillo-Corrales fight is widely regarded as one of the greatest battles in boxing history. The two warriors stood toe-to-toe, exchanging brutal combinations and demonstrating incredible heart and determination. Ultimately, Corrales emerged victorious by TKO in the tenth round, but both men earned Fight of the Year honours from The Ring and the Boxing Writers Association of America.

Castillo would defeat Corrales in a rematch later that year, but a third bout never materialized due to weight issues. As Castillo moved up in weight, he continued to face top opposition, including a memorable clash with British superstar Ricky Hatton in 2007, which ended in a devastating fourth-round knockout loss for the Mexican warrior.

In the twilight of his career, Castillo faced the likes of Timothy Bradley and Alfonso Gomez before announcing his retirement in 2010. Although he would fight a few more times, his legacy as one of his generation's greatest Mexican boxers and most exciting fighters was already secure.

José Luis Castillo's career was defined by his unwavering spirit, his ability to overcome adversity, and his willingness to take on the sport's biggest challenges. His battles with Floyd Mayweather Jr. and Diego Corrales will forever be etched in the annals of boxing history, serving as a testament to his skill, heart, and enduring impact on the lightweight division.