eat someone for breakfast
US /iːt ˈsʌm.wʌn fɔːr ˈbrek.fəst/
UK /iːt ˈsʌm.wʌn fɔːr ˈbrek.fəst/

1.
to easily defeat or overcome someone, especially in a competition or argument
:
•
Our team is so strong, we're going to eat them for breakfast in the championship.
•
Don't worry about the interview; you'll eat him for breakfast.