Nicknamed "Little Red", he was a popular Featherweight champion during the 1970s, and a WBC Featherweight Champion.
His first professional fight was a one-round knockout of Steve Flajole on May 27, 1971.
He was inducted into the California Boxing Hall of Fame in 2005 and the International Boxing Hall of Fame in 2010.
His brother is Welterweight fighter Ernie Lopez.
He lost in two consecutive fights to Salvador Sanchez in February and June of 1980.