The wheelchair-bound woman said Williams's security team spotted her crying in the audience and invited her backstage.
She insisted she was crying tears of joy, and laughing for the first time since she learned she would need a new kidney.
Williams was so moved by the woman's story he handed her a folded up sheet of paper -- a signed note containing 10 $100 bills.
Although the woman admitted she suspected at first he was handing her weed, she said the money was an "awesome surprise."
2014: The Year in Music [PHOTOS]