Chicago Teachers Union President Karen Lewis chats with students before class on the first day of school. (E. Jason Wambsgans, Tribune photo / September 11, 2011)

The woman who once promised a boxing match with Mayor Rahm Emanuel for the rights of teachers and the hearts of Chicago's public school children is getting up off the mat.

Bullied and bludgeoned by weeks of intense public debate over a longer school day, Chicago Teachers Union President Karen Lewis fought back Friday by filing an unfair labor practices complaint against Chicago Public Schools leadership and accusing Emanuel of trying to intimidate her in a profanity-filled tirade recently at City