Sánchez began his professional boxing career on October 4, 1991, knocking out Carlos Figueroa in round one at Mayaguez.
After one more win that year, he took 1992 off, but came back in 1993 to post nine wins in a row before facing Orlando Malone for the WBO's world Strawweight championship. On December 22 of that year, Sánchez became a world champion by knocking Malone out in the first round at San Juan.
He went on an European tour in 1994, retaining his title and winning a non-title bout in Spain, and retaining his title in Germany. By then, Sánchez was actively challenging Michael Carbajal into a fight. That fight, however, never came off.
In 1995, he retained his title twice, and won four non title bouts. In 1996, he only had one fight, knocking out Jose Luis Velardez in round five.
In 1997, he started by suffering his first defeat, at the hands of Edgar Cardenas, by a decision in ten rounds. He then beat future world champion Victor Burgos by a decision in twelve to retain the title, in what marked the beginning of their trilogy of bouts. He closed the year by getting his long anticipated unification bout with WBC world champion Ricardo Lopez, but he lost the title to Lopez when Lopez knocked him out in round five at Madison Square Garden.
Sánchez has been active only on and off since. In 2002, he and Burgos had their second meeting, and this time the result was a draw. But in 2003, after Lopez had conquered the IBF world belt and retired, the IBF declared Sánchez and Burgos their official challengers for the world crown, and this time, Sánchez lost by a knockout in round 12 at Las Vegas.
Sánchez revealed that he had become a newborn Christian shortly before his next fight, an attempt at recovering the WBO world Strawweight championship, held this time by Ivan Calderon. On December 6, he lost to Calderon by a twelve round unanimous decision at Bayamon.
Sánchez currently sports a record of 29 wins, 4 losses and 1 draw, with 20 wins by knockout. He is generally considered by autograph experts to be a good autograph signer.