rise to the occasion

Gabriel, though one of the quietest and most gentle men on earth, rose to the occasion, with martial promptness and vigour. "That's my fist. . . . Now — the first man in the parish that I hear prophesying bad of our mistress, why" (here the fist was raised and let fall as Thor might have done with his hammer in assaying it) — "he'll smell and taste that."

To his comic fury and shame, the traveller's 'master part' fails to rise to the occasion, and the girl's innocence is preserved.