Complex sentence: Blissett and his team mates made the headlines in the 1982--83 season as they surprised many by proving successful in the First Division and briefly led the league in the autumn before finishing second to Liverpool and qualified for the UEFA Cup.
Split into simpler sentences: Blissett and his team mates made the headlines in the 1982--83 season as they surprised many by proving successful in the First Division. Watford briefly led the league in the autumn, before finishing second to Liverpool and qualified for the UEFA Cup.