The singer, whose controversial comeback video for the song 'Hard Out Here' mimics Robin Thicke's 'Blurred Lines', says her feud with American rapper Azealia came at the right time.
She told Nick Grimshaw on Radio One: "There was one person that was particularly nasty to me on Twitter for no apparent reason.
"And I was struggling with finding my voice - not my singing voice, because I've never found that - but my writing voice.
"And this one person was being particularly horrible to me and I happened to be in a studio session at the time, and it was just brilliant because it ignited this juvenile flame in my bell. So thank you, Ms. Banks."
Lily, who has confirmed she will be playing Glastonbury 2014, was involved in a Twitter row with the 22-year-old star in July this year.
They started a war of words when the '212' singer accused Lily of having a drug habit and declared her husband Sam Cooper looks like a "thumb".
The vicious spat kicked off when one of Azealia's fans forwarded her one of Lily's tongue-in-cheek tweets from April 2012.
It read: "YOURE ALL JUST JEALOUS CAUSE IM SOOOOOOOO FUCKING BEAUTIFUL AND HAVE SUCH A PRETTY FACE. (sic)"
Azealia took offence to the comment, and tweeted: "Weak. She can't talk though. Not when I met her coked up at yoyo ... And NOT with that ugly husband she has. (sic)"
Lily appeared to want to let the comment lie, until Azealia bit back, writing, "Your husband looks like a thumb".
The unprovoked attack on Sam - who wed Lily in June 2011 - unleashed the wrath of the 28-year-old singer, who slammed Azealia's music.
Lily scoffed: "Not even gonna @ her but if she wants to talk about weak , I'm sure her record sales to date should suffice. One hit wonder."