Fight your/somebody’s corner
Definition 1 of 1
Pro Tip 1/3Emotional Support
Used to show you have someone's emotional backing when they face opposition or criticism. 
Despite the backlash, my team fought my corner passionately.
Pro Tip 2/3Difficult Situations
Implies defending a stance when it is particularly challenging or when facing hostile views. 
She had to fight her corner to get the project approved.
Pro Tip 3/3Assertiveness
Suggests being assertive and not backing down easily in debates or when questioned. 
In the debate, he fought his corner with surprising tenacity.