[2] Núñez began her career by knocking out Claribel Ferreira in three rounds, on 9 June 2000, at Santo Domingo.
Three decision wins followed, including one over previously undefeated Marylin Hernandez, before she fought for the first time at the "Teo Cruz" coliseum, also in Santo Domingo.
New Jersey was a logical choice for Nunez when it came down to choosing a state where to live in the United States for her: both New Jersey and New York have a large group of Dominican people, which would mean good crowd backing for Nunez whenever she fought in the US, particularly around the New England area.
Núñez travelled to Bermuda for her first fight of 2004, defeating Teresa Perozzi there by a six-round majority decision on 12 June.
On 30 July, she fought Laila Ali in Louisville, Kentucky, being defeated by a ninth-round knockout by the world champion.