v. To come or bring to a special or unexpected ending; climax. John batted three runs and topped off the game with a home run. Mary hadn't finished her homework, she was late to school, and to top it all off she missed a surprise test. George had steak for dinner and topped it off with a fudge sundae.
TOP OFF
Meaning of TOP OFF in English
American idioms English vocabulary. Английский словарь американских идиом. 2012