On July 30, 2004, Solis challenged WBO Light Flyweight champion Nelson Dieppa but lost the twelve round bout.

On May 19, 2007, Solis defeated former WBC world champion José Antonio Aguirre via an 8th round technical knock out.

Following that victory, Solis defeated former champion Eric Ortiz by a 10-round unanimous decision at the Grand Sierra Resort in Reno, NV commemorating the 100th anniversary of The Johnson-Jeffries Fight.

On December 18, 2010, Solis fought IBF light flyweight champion Luis Alberto Lazarte to a controversial majority draw in Argentina.

The referee, Max Parker, who had trouble communicating with the fighters in Spanish, warned Lazarte throughout the bout, however, he ultimately only deducted two points from the defending champion.

In October 2011, he got into a street fight against fellow Mexican boxer and four-division champion Canelo Álvarez resulting in a broken jaw.