Arroyo, of Puerto Rican descent, was born on the south side of Youngstown, Ohio, a steel-manufacturing center near the Pennsylvania border.
Arroyo, a late substitute for Cornelius Boza Edwards, staggered Brown with two blows to the head, prompting referee Larry Hazzard to stop the fight.
On September 1, 1984, Arroyo successfully defended his title against Charlie "White Lightning" Brown, in a bout held in Struthers, Ohio.
Mancini took a break from boxing for several years after losing his title, and by the time he re-entered the ring, Arroyo's career had waned considerably.
Both men were on hand, however, when fellow Youngstown native Kelly Pavlik took the WBC and WBO middleweight world championship in Atlantic City on September 29, 2007.