[3] A skilled boxer-puncher, De La Rosa debuted on 15 May 1980 in San Juan, Puerto Rico, against Jesus Rosado, who had lost one and drawn (tied) one of his two previous professional contests.
[4] De La Rosa's first fight in his home country took place on 20 October 1980, against the debuting Ruben Dario Herasme in De La Rosa's third contest as a professional, which was held in Santo Domingo, as part of a program where the main event was Miguel Montilla's ninth-round technical knockout win over former WBA world junior-welterweight champion Alfonso Frazer of Panama.
Herasme and De La Rosa had an immediate rematch, which took place 20 days after their first match, on 10 November 1980 at Santo Domingo as the main event of a program that also included future WBA world junior flyweight champion Francisco Quiroz.
[13] De La Rosa returned to title contention by winning ten fights in a row after the Esparragoza defeat; included among those was a win over Adriano Arreola of Mexico on 17 April, 1986 at New York City's Madison Square Garden's Felt Forum to claim the WBC Continental Americas' junior lightweight title by a seventh-round technical knockout,[14] and a defense of that belt against American Jackie Beard, on 10 July of the same year, a twelve-rounds split decision victory for De La Rosa, also at the Felt Forum in New York.
[15] De La Rosa challenged Rocky Lockridge, who had a record of 41 wins and 5 losses, for the American's IBF world junior lightweight championship on 25 October, 1987 at the Convention Center in Tucson, Arizona.
De La Rosa followed with a third fight against Ruben Dario Herasme, against whom he emerged victorious for the third time, on 26 February, 1988 in Santo Domingo by four-rounds decision.
De La Rosa closed his professional boxing career after losing to Roberto Sierra, a boxer with a modest record of 3 wins and 4 losses, on 26 April, 1996, at the Music Fair, in Westbury, New York, in a card headlined by a Trevor Berbick fight.