Englishpast master
noun
the manager was a past master at recharging faltering spirits:
expert, virtuoso, master, wizard, genius, artist, old hand, adept, professional, doyen, veteran, maestro, connoisseur, authority, grandmaster, master hand, skilled person;
informal ace, buff, pro, star, whiz, hotshot, ninja;
British, informal dab hand;
North American, informal maven, crackerjack.