They then upset South by twelve points .
They then came back on a windy day to defeat East Fremantle by two points in the 1955 WANFL Grand Final for their first premiership in forty - eight years .
They then upset South by twelve points and came back on a windy day to defeat East Fremantle by two points in the 1955 WANFL Grand Final for their first premiership in forty - eight years .