fechar com chave de ouro

Literally, “to close with a golden key”.

fechar com chave de ouro (first-person singular present fecho com chave de ouro, first-person singular preterite fechei com chave de ouro, past participle fechado com chave de ouro)

1. (idiomatic) to conclude something already successful in an efficient, advantageous or otherwise positive way

• a cereja do bolo