In February 1928, following the dismissal of Metropolitan Christoforos Knitis, Father Papathanasopoulos was sent to Sydney as administrator until a new bishop arrived.
He served as a parish priest for five years in Sydney and for fourteen in Melbourne until he was appointed the third Metropolitan of Australia and New Zealand on 22 April 1947.
His reign was cut short when he died on 2 August 1958 in the Alfred Hospital, Melbourne, from injuries received in a car accident two days earlier.
[2] His funeral service was presided over by Archbishop Athenagoras of Thyateira at the Cathedral of St Sophia, Darlinghurst, Sydney.
He now rests in the Orthodox section of Rookwood Cemetery in an area for clergy, just behind the sanctuary of Saint Athanasius Chapel.