He posted two more wins in a row, one by knockout, then lost for the first time as a professional, beaten by Herminio Adorno by a decision in five rounds on May 22.
Rivera won five of his next six bouts before fighting abroad for the first time, losing by a ten-round decision to Enrique Sanchez at Santo Domingo, Dominican Republic, on October 15, 1982.
Rivera won his next four fights, including a seventh-round knockout victory over Manuel Santos as part of the Wilfredo Gómez-Eladio Santana fight's undercard at the Roberto Clemente Coliseum on December 14 of that year, and his Madison Square Garden debut, a win over Vincent Christian by a fifth-round knockout on July 26, 1984, at the Garden's Felt Forum Arena.
On February 2, 1985, Rivera re-established himself as a top ranked boxer when he knocked out Alberto Mercado in seven rounds as part of one of Victor Callejas' title defense undercards.
He lost his next fight after the bout with Bou Ali, but rebounded with four straight wins, including a third-round knockout over future world champion Giovanni Parisi on November 10, 1990, in Monsano.
Rivera then embarked on another winning streak, which included a second-round knockout over Argentine hopeful Fabian Tejada on March 6, 1995, in Inglewood, California.
He also lost to Diosbelys Hurtado, but, on October 25, 1997, he did draw over ten rounds with former WBO world Jr. Welterweight champion, fellow Puerto Rican Sammy Fuentes.
The second athlete to have his mortal remains exposed there was Félix Javier Pérez, a basketball player who was murdered later that year while trying to defend a neighbor from robbers.