The board were able to persuade Spiers to rejoin the club, and he led a side built around players brought through by his youth system to the First Division in 1952. After two seasons in the top tier, Spiers left the club to take over at Crystal Palace. He was replaced by Trevor Morris, a former Cardiff player whose career had been ended due to a broken leg sustained in a wartime friendly. Morris claimed his only silverware during the 1955–56 season by winning the Welsh Cup but was unable to prevent the club's relegation from the First Division the following year. He left the club in 1958 to manage Swansea Town and was replaced by his assistant, Bill Jones, who had previously managed Barry Town and Worcester City. Jones led the team back to the First Division in 1960 where they spent two years before being relegated. After a disappointing start on their return to the Second Division, Jones left the club. Jimmy Scoular was appointed as Jones' replacement but suffered a difficult start after failing to win any of his first 12 matches in charge. Although Scoular never won promotion during his nine years in charge, his spell at the club coincided with its first entries into European competition in the UEFA Cup Winners' Cup by winning the Welsh Cup, a feat he achieved seven times during his tenure. He led the team to the semi-final of the Cup Winners' Cup during the 1967–68 season, the furthest a Welsh team has ever advanced in a continental competition, but continued struggles in the league saw him dismissed in November 1973 during his tenth season in charge.
