Spanish defender Juan Legarreta. In 1927, following the merger of the National Football Federation occurred the year before, the championship was called Liga Central de Football. Because of the participation of too many clubs, league was divided into two categories in 1927 and 1928: the Serie A and Serie B. The club also was in the Serie A. In 1928, Unión Deportiva Española was awarded its second title, after winning the Liga Central de Fútbol. In May 1933, Unión Deportiva Española with Colo-Colo, Santiago Badminton, Audax Italiano, Green Cross, Magallanes and Santiago National, were the clubs that founded the Professional League of Chile, part of the Asociación de Fútbol de Santiago. In the Apertura Championship of the same year, Unión achieved the runner-up, after lossing the final against Colo-Colo, in a 2–1 loss. In the Official Championship, the club finished in the fourth place of eight teams. In the next year, with the final fusion of Centro Español de Instrucción y Recreación and Unión Deportiva Española, in 1934, the club take definitely the name of Unión Española (being re–founded symbolically on 9 December 1935). In 1939, Unión only played one match in the Primera División 1939 (against Colo-Colo), under the name of Central, in the first week of the tournament. Because the Spanish Civil War of this year, the club's leadership entered in recess for one year. In the next season, Unión had a youth squad during the Primera División tournament of 1940, but the team finished in the tenth place. In 1943, Unión won his first professional title in the Primera División. After the runner-up achieved in 1945, 1948, in 1950, the team once was runner-up, after lossing the Championship play-offs against Everton for 1–0, with a goal of René Meléndez. Unión once win the Primera División title in 1951 under the Spanish coach Isidro Lángara. This title was the second in Unión Española's history. Golden Age Under the Argentine Nestor Isella as coach, Unión Española was the runner-up of the Primera División Chilena in 1970, after a loss in the final match against Colo-Colo in January 1971. However, being the runner-up allowed to Unión to participate for the first time in the Copa Libertadores. In the Copa Libertadores 1971, the club finished first in the group stage, qualifying for the semi-finals, but Unión was eliminated in the group in the last position. Whilst in the local tournament, Unión