Complex sentence: In 1927 they defeated Arenas Getxo in the only all-Basque final to date, also being runners-up in 1922, losing 5--1 to FC Barcelona.
Split into simpler sentences: In 1927 they defeated Arenas Getxo in the only all-Basque final to date. In 1922 they were runners-up, losing 5--1 to FC Barcelona.