How to get revenge like Blair Waldorf?

I have a friend who lied to me and when I told her that she completely contradicted herself and lied to me she stopped talking to me. She since has deleted me from all the social networking sites, spreading rumors to people telling them I made up a rumor about her and spread it to everyone. Which is lies. Tonight is a party and she will be there. What is the best Blair-like way to make her look wrong. Because she is awful and spreading viscous stuff :( and at first i was being nice to her but now she is being mean i'm done. so i need help :) (blair off gossip girl)