The last hope in a desperate situation, you're last shot to make something work.
Usually works because of the power of sheer desperation.
girl 1: weren't you gonna dump your bf today?
girl 2: yea...but he got down on his knees with a basket of roses and begged me to forgive him...
girl 1: Oh wow. I guess he pulled a prayer of the refugee. You didn't have a chance.