play into someone's hands
US /pleɪ ˈɪntu ˈsʌmwʌnz hændz/
UK /pleɪ ˈɪntu ˈsʌmwʌnz hændz/

1.
fare il gioco di qualcuno
to do exactly what your opponent wants you to do, so that they gain an advantage over you
:
•
By arguing with him, you're just playing into his hands.
Discutendo con lui, stai solo facendo il suo gioco.
•
The opposition's mistakes played right into the government's hands.
Gli errori dell'opposizione hanno fatto il gioco del governo.