Juan Domingo Roldán (born March 6, 1957) is an Argentine former boxer whose nickname was Martillo (Hammer). Roldán was very famous across Latin America during the 1980s, many articles about him appearing on Ring En Español magazine.
On May 11, 1979, Roldán fought the full distance in one of his bouts for the first time, when rival Hugo Obregon went ten rounds with him. Roldán won the fight on points. On September 21, 1979, Juan Carlos Borgado became the first boxer to defeat Roldán, winning a ten-round decision over Roldán.
Out of his next eighteen bouts, he won seventeen and drew (tied) once. Then, he challenged Jacinto Fernandez on March 13, 1981, for the Argentine Middleweight title. He won the national title with a twelve-round decision over Fernandez. In his next fight, he beat José María Flores Burlón, a boxer who would later challenge Carlos De León for the world's Cruiserweight title. Roldán won six more fights and drew one before challenging José Maria's brother, Carlos Flores Burlón for the South American Middleweight title, on February 12, 1982. He won the title with a second-round knockout.
Before 1982 was over, he would see more action, retaining his Argentine Middleweight title with a first-round knockout of Marcos Perez, but losing on a disqualification in three rounds to Ricardo Arce. In an immediate rematch, Roldán put his Argentine title on the line and this time, he avenged his defeat to Arce with a two-round knockout win. After five more wins in a row, he fought Juan Carlos Peralta, with the fight resulting in a three-round no contest.
After this win, Roldán was ranked number 1 by the major boxing organizations, and many fans began to speculate as to what would happen if he and Hagler met. The contracts for the fight were signed, and the fight finally came off on March 30, 1984. Roldán in this fight had the moment that probably defines his career better. Seconds into round one, as Hagler was bending to duck a Roldán punch, Roldán struck him in the back of the head, and Hagler went to the floor. Referee Tony Perez officially ruled it a knockdown, making Roldán the first man to drop Hagler. This was a controversial knockdown, however, many fans, magazines and websites have tirelessly claimed that the knockdown was actually a slip and not a knockdown. Hagler got up and proceeded to beat Roldán by a ten-round technical knockout, and Roldán announced his retirement from boxing in October of that year. Roldán remained the only guy to officially score a knockdown against Hagler.
In 1986, he reconsidered his decision and made a comeback. He won twelve bouts in a row, including one over James Kinchen, before he challenged for a world title again. On October 29, 1987, at Las Vegas, Thomas Hearns became the first boxer to win world titles in four different divisions when he beat Roldán in four rounds by knockout, but not before Roldán had Hearns in trouble in round three.
On September 16, 1988, Roldán beat former world Middleweight champion Hugo Corro by a knockout in round one in Mar del Plata, securing a third world title shot, against Michael Nunn, on November 4 of that year. Roldán lost what turned out to be his last fight, by a knockout in round eight.
Roldán retired with a record of 67 wins, 5 losses, 2 draws and one no contest, 47 of his wins being by knockout.