Edwin Rosario, who was a world boxing champion in two weight divisions, might have achieved even more had he not spent so long struggling with his personal demons. His death, in mysterious circumstances at the age of 34, came at a time when he was preparing for his next comeback fight in Miami in January. Cocaine abuse was suspected, but denied by his friend the WBA featherweight champion Wilfredo Vazquez.
At his peak "Chapo" Rosario was a heavy-punching lightweight who held both the World Boxing Council and the World Boxing Association titles. Only his failure to master the English language spoiled attempts to turn him into an internationally marketable personality.
Early in his career he was snapped up by the New York partnership of Jim Jacobs and Bill Cayton, who masterminded Mike Tyson's rise to fame in the mid-1980s. However, it was impossible to project Rosario as fully as the Puerto Rican had hoped, and they parted company. Nevertheless, his boxing ability was never in question.
Rosario was born in the San Juan suburb of Santurce, and his family moved to Toa Baja when he was three. Edwin was educated at a local high school, where he met his future wife, Alma. He also trained in a boxing gym run by Manny Siacca, who taught him how to fight and eventually helped negotiate the deal with Jacobs and Cayton.
By then he was already a professional - he had made a winning professional debut at 16, and was still only six weeks past his 20th birthday when he won the World Boxing Council lightweight title by outpointing the Mexican southpaw Jose Luis Ramirez over 12 rounds in San Juan in May 1983.
In a rematch the following year Ramirez stopped him, but in 1986 he gave the extraordinary Hector Camacho a gruelling 12 rounds before the self- styled "Macho Man" was given a bitterly disputed decision. Both were Puerto Rican, but Camacho had been raised in New York. In effect, Rosario claimed the decision was racially biased, an argument that was never taken seriously.
Rosario won the World Boxing Association lightweight title with a stunning second-round knockout of Livingstone Bramble in Miami in September 1986, and remained champion for 14 months until he was stopped by the legendary Mexican Julio Cesar Chavez in the 11th round of one of the best fights of the decade.
If anything, that performance enhanced his status rather than diminished it, and two years later he regained the WBA title by stopping Anthony "Baby Face" Jones of Detroit. By the turn of the decade, however, his life was beginning to crumble. He lost his title, moved up to light-welterweight and was briefly recognised as champion by the WBA, but by 1992 was in crisis.
A younger brother, Papote, had been forced to abandon a promising professional career because of drug addiction, and rumours began to surface that Edwin had a cocaine problem. Eventually, he parted from his wife, who took their daughters Ruby and Glorisabel with her, and he drifted into retirement.
At one time he was said to be a cock-fighting entrepreneur in Toa Baja, but his weight ballooned as he struggled to overcome his personal difficulties. His comeback in July 1997 was sad. Although he won two fights, and talked optimistically of another world championship, he was an elderly athlete. It could never have happened.
Poignantly, he said at his peak in 1986: "I won't be in this game for too long, and when I do get out, I want to be a positive influence with the kids in Puerto Rico. No fancy cars or flashy clothes for me, I just want to take care of my family and do good for others."