Professional Football Goalkeeper. Nicknamed "El arquero negro" because of distinctive black uniform that he wore in each match. Regarded by many one of the best goalkeepers of all time, he started his career in 1961, at the age of sixteen to Racing de Montevideo. In 1964, after an excellent test as goalkeeper of Uruguay to the South American Youth Championship in Colombia, he was acquired by Club Atlético Peñarol. He was initially included in the team as a reserve of Luis Maidana, but earned soon the starting spot after an excellent performance in the playoff semi-final of the Copa Libertadores on March 31, 1965 against Santos of Pelé. In the same year, he won his first national title crowned in 1966 with the triumph in the Copa Libertadores. A year later comes the second national title during the 1967 season during which he set a undefeated record of 985 minutes in 11 matches. The following year, Peñarol won championship again, Mazurkiewicz sets a new record, conceding only five goals throughout the season. In 1970, he took part with his national team to the Fifa World Cup in Mexico, Uruguay finished the tournament in fourth place while Mazurkiewicz was named best goalkeeper of the tournament. In 1971, he left the Peñarol to move to the Atlético Mineiro in Brazil, the season ended with the victory of the Brazilian championship. At the end of the World Cup 1974 in Germany where he was again voted by the critics as the third best goalkeeper in the world tournament, remained in Europe, and played for two seasons at Granada in Spain. In 1978, he returned to South America to play with the Corporación Deportiva América until 1979. In 1979, he moved to Club de Deportes Cobreloa in Chile, and in 1981 returned to Peñarol. In that same season closed his career winning at age of thirty-six, one last national title. He died in a hospital in Montevideo after being in a coma because of a respiratory failure.