In 1955, that move was made, and a wonderful new clubhouse and grounds were opened on College Drive (off Fortfield Road) and so began a golden era in St Mary’s history. It took only a few years to taste success, for in 1957-58 season under the inspired captaincy of Joe Fanagan and with wonderful players like Ned Carmody, Vincent Mc Govern, Sean Cooke, Jack Bagnall, the Hussey twins, Dick Whitty, Ken Wall and Nicky Corrigan, brought home to College Drive, the Leinster Senior Cup for the first time. The LSC, now the Leinster Senior League Cup, at that time was the most prestigious trophy and the most difficult to win in Irish rugby.
The sixties saw a stream of cups come home to St Marys at junior level and then having been so close on a few occasions, in 1969 the great Sean Lynch ,who afterwards became be our first international and British and Irish Lion, drove his super team to win the LSC again. During the sixties, the club also had many provincially capped players and the club was growing in strength and status all the time.