Foil
.That which sets off something to advantage. The allusion is to the metallic leaf used by jewellers to set off precious stones. (French, feuille; Latin, folium; Greek, phullon, a leaf.)
He foiled me. He outwitted me.
“If I be foiled, there is but one ashamod who never was gracious.”—Shakespeare: As You Like It, i. 2.