The 'Hard Out Here' singer admits that her song-writing ''sounded terrible'' during her four year hiatus from music, but claims her Twitter spat with the '212' hitmaker - which started after the New York rapper called her children ''ugly'' - inspired her to pen new material.
Lily, who has daughters Ethel, two, and 15 month old Marnie, with husband Sam Cooper, told The Sun newspaper: ''I tried to write through my pregnancy with my youngest, but the hormones were really weird and it was just really forced and sounded terrible.
''Then it wasn't until I stopped breastfeeding, six months on Azealia tweeted me on Twitter, that I was like, 'Yes you know who I am.' ''
Azealia also took a swipe at the 'Not Fair' singer's husband Sam by saying he looks like a ''thumb'', which forced Lily to brand the rapper a ''one-hit wonder''.
However, Lily insists the harsh comments all contributed to her comeback record 'Sheezus'.
She explained: ''I found my voice again then, I just bashed it all out. It was like two years of writing before I found it.''
Many ticket-holders couldn't get into the O2 Arena show on Tuesday night (September 19th) because they didn't bring photo ID to match their booking.
An album re-release, a new song and a documentary mark the singer's legacy this year.
The actor plays the titular hero in the forthcoming adaptation.