a zădărnici planurile cuiva

1. to frustrate / to thwart / to upset smb.'s designs / plans

to defeat / to discomfort smb.'s schemes

to play hell / the deuce with smb.'s plans.

2. to upset smb.'s applecart

to put a spoke / a spanner in smb.'s wheel

to throw a spanner into the works

to spike smb.'s guns

to take the wind out of smb.'s sails

to break the eggs in smb.'s pocket

to kick / to strike / to throw / to trip up smb.'s heels

to knock smth. into a cocked hat.