Complex sentence: In 1979, Lloyd and Forest won the European Cup and retained the League Cup, the only disappointment in 1979--80 coming in the League Cup, where they reached the final for the third season running only to lose to Wolverhampton Wanderers.
Split into simpler sentences: In 1979, Lloyd and Forest won the European Cup and retained the League Cup. In the 1979--80 League Cup yhey reached the final for the third season running but lost to Wolverhampton Wanderers.