Complex sentence: They also took part in the Coupe de France, the only national competition at that time: in 1925, they reached the last sixteen where they fell to Lille after eliminating the then-dominating Red Star Paris.
Split into simpler sentences: They also took part in the Coupe de France, the only national competition at that time. In 1925, they reached the last sixteen, where they fell to Lille after eliminating the then-dominant Red Star Paris.