Katy Perry Changed "Part of Me" Lyrics at Grammys for Russell Brand

There's no doubt about it: Katy Perry rocked Grammy night, that's for sure! After she belted out her new revenge anthem, "Part of Me," i was revealed that she changed the song's lyrics specifically to biting words aimed at ex-husband Russell Brand.

OK! NEWS: KATY PERRY DEBUTS NEW SINGLE "PART OF ME" & COMPLETELY DISSES RUSSELL BRAND AT GRAMMYS! At the 2012 Grammy Awards, music's biggest spotlight, Katy crooned the words, "You chewed me up and spit me out/ Like I was poison in your mouth." The theme of the song — about getting over a toxic relationship — seemed like perfect timing considering she and Russell recently signed divorce papers. According to The New York Post, however, the "Firework" singer co-wrote the song back in 2010! Other original lyrics were a little less caustic: "You can keep the dog/ I never liked him anyway." On Grammy night, she changed those lyrics as well, singing, "You can keep the diamond ring/ it don't mean nothing anyway." OK! NEWS: KATY PERRY & RUSSELL BRAND SIGN DIVORCE PAPERS What a difference a year makes! A mere 12 months ago, on that same stage, Katy was lifted into the air on a swing as footage of her blissful Indian wedding aired behind her. This makes us wonder: considering Adele won big for her breakup anthem, "Rolling in the Deep," we wonder if "Part of Me" will become a new revenge classic? What do you think?