Shortly after going professional in 2002, Gilbert Melendez established himself as one of the fastest-rising MMA prospects in the world at 155 lbs., becoming the first WEC Lightweight Champion in his fourth professional fight against Olaf Alfonso in 2004. Melendez would continue to put on dominant performances over the next three years, running his professional record to 13-0, with notable wins over Clay Guida and Tatsuya Kawajiri, before losing the first fight of his career to Mitsuhiro Ishida in Saitama, Japan in 2007.

After another loss, this time to Josh Thomson, cost him his Strikeforce Lightweight Championship in 2008, Melendez was forced to regroup. He returned with an obvious chip on his shoulder and went on a tear in the promotion, kicking his already high level of intensity up another notch and winning three straight fights in convincing fashion. Melendez blasted out Rodrigo Damm, avenged his losses to Ishida and Thomson, and regained the Strikeforce title in 2009. Next up, an eagerly awaited title defense between Melendez and Shinya Aoki on CBS turned into a coronation for "El Nino," with the Japanese grappler unable even to get to square one with his ground game over five long rounds.

Melendez is known for his finishing ability, wrestling control, and ceaseless fury when he steps into the cage. He is one of the best in the world at 155 lbs.