He had one bout in 1997, an eleventh round knockout over undefeated future interim champion Songkram Porpaoin (twin brother of Chana), for his fourth title defense.
A rematch was set for later in the year, however, the fight was in jeopardy of taking place as Alvarez failed to make weight by 3 1/4 pounds.
Álvarez then moved up to the 108 lb division and won his following three fights, including a decision victory over future champion Tomás Rojas.
On August 12, 2000, he lost by seventh round disqualification for repeated low blows to Beibis Mendoza for the vacant WBA light flyweight title.
In 2004, he was stripped of his WBA and Ring light flyweight titles prior to a fourth meeting with Mendoza, due to his failure to make weight.