Edwin "Chapo" Rosario Rivera (; March 15, 1963 – December 1, 1997) was a Puerto Rican professional boxer who competed from 1979 to 1997. He is a world champion in two weight classes, having held the WBC lightweight title from 1983 to 1984, the WBA lightweight title twice between 1986 and 1990, and the WBA super lightweight title from 1991 to 1992. Known for his exceptional boxing skills, dynamite right hand and rock solid chin Rosario's final record stands at 47-6
Rosario was posthumously inducted into the International Boxing Hall of Fame in 2006.

Early life and career
Edwin Rosario was born in Candelaria barrio, Toa Baja, an extremely poor barrio on the north coast of Puerto Rico. Rosario's older brother Papo became a professional boxer, beginning what looked like a promising career. Edwin and Papo were the sons of Antonio Rosario and Elizabeth Rivera. They also had three sisters.

His boxing manager and coach (trainer), Manny Siaca Sr., had noticed the younger Edwin Rosario's talent when the boy was 8 years old. Inspired by his brother Papo, Chapo Rosario, as he became known in the world of boxing, had a stellar amateur boxing career.

Professional boxing career
Chapo's brother Papo died unexpectedly, purportedly due to drugs, two years after his entry into professional boxing. Rosario persevered, wanting to honor his brother's memory by winning a world championship. He scored big knockout wins over Young Ezzard Charles and Edwin Viruet. He beat Charles in three rounds on the Benitez-Duran undercard in January 1982 in Las Vegas. He also defeated Viruet in three rounds; that opponent had boxed 25 rounds against Roberto Durán-including a world lightweight championship bout-without being knocked out.
Rosario eventually gained a record of 21–0 with 20 knockouts. This led to talks of a title fight against World Boxing Council (WBC) lightweight champion Alexis Argüello, to be held in Miami. But Argüello relinquished the title in order to move up in weight to challenge junior welterweight champion Aaron Pryor.
Boxing champion
With Arguello moving divisions, Rosario was matched with Mexico's José Luis Ramírez on May 1, 1983 for the vacant WBC lightweight title. Rosario seemed to have the momentum over the first half of the fight, but tired down the stretch to make for a very close outcome. The judges, as well as most of the public present, felt Rosario had done enough to win. He became world lightweight champion by the unanimous score of 115–113 on all 3 judging cards. Rosario injured his hand during the fight and needed surgery, for which the World Boxing Council gave him a dispensation.
He didn't return to the ring until 1984. In his first defense of the title, he faced Roberto Elizondo, who had lasted 7 rounds with Argüello in a previous world title challenge and was expected to give him a tough fight. Rosario knocked out Elizondo in one round. Howard Davis Jr proved more of a challenge – Davis Jr was ahead on all scorecards with ten seconds remaining in the bout, but was dropped by Rosario for the second time in their fight at that point, and lost a split decision.
A rematch with Ramírez was scheduled, again in San Juan, Puerto Rico, on November 3, 1984. Rosario dropped Ramírez once in round one and again in the second, but the challenger got off the canvas to take Rosario's title away with a fourth-round TKO. This was Rosario's first defeat. Some fans felt he never fully recovered, although he won three more championships.
Rosario won a comeback fight against Frankie Randall, the future world champion, in London. He had to wait another year before an opportunity to regain the title. On June 13, 1986, he met the world champion Hector 'Macho' Camacho at Madison Square Garden in New York. The fight was televised by HBO, and although Rosario shook Camacho badly in the fifth round and rallied down the stretch, Camacho swept the middle rounds. The judges, in a split decision, awarded Camacho the fight.
Because of the closeness of that bout, the WBA gave Rosario a chance to challenge Livingstone Bramble, one of two other world lightweight champions (the other one being the International Boxing Federation's Jimmy Paul). Rosario went to Miami and defeated Bramble by knockout in the second round to become world lightweight champion for the second time. His pose, raising his arms after the fight, became The Ring magazine's cover for the next month — the only time Rosario was featured on its English-version cover.
Rosario defended the WBA lightweight title against fellow Puerto Rican Juan Nazario with a knockout in eight in Chicago.





