Known as "Mantequilla", a name given to him by his famous trainer Jose 'Pepe' Correa, Brown was two-weight world champion in the welterweight and light-middleweight divisions, and at one point considered one of the best pound-for-pound fighters in boxing.
Brown began his career in 1982 at the age of 19 and ran off a string of 21 consecutive victories, prior to losing a split decision to Marlon Starling for the USBA welterweight title in 1985.
Simon won three consecutive bouts, including a victory against undefeated former Olympian Shawn O'Sullivan to line up a shot at the vacant IBF welterweight title against Tyrone Trice.
In his next bout, Brown lost a hard-fought ten round decision to former WBA welterweight title holder Aaron Davis.
In August 1996, Brown challenged undefeated WBO middleweight title holder Lonnie Bradley and lost a unanimous decision.