The singer - famed for recording in her native London voice - was spotted by the US hitmaker when her song ' Who'd Have Known' was used as hold music, leading to him asking her to appear on his single '5 O'clock'.
T-Pain said: "I picked Lily for the accent, I think that's what I love the most, the accent."
Lily has said she is flattered the sample - which takes the first lines of her track - was picked by T for his song.
She said: "I love '5 O'clock '! It's absolutely brilliant, and I'm really flattered by what he did to my original track!
"I heard how T-Pain first heard my song when he was stuck on hold and had no idea who I was or who was singing the song, but after he hung up he went on a mission to find out who recorded it."
Lily is also amazed how popular the melody of that particular song is proving, pointing out it has already passed from Take That to her to now over to the US.
She explained: "When I first heard the T-Pain track '5 O'clock', I was really impressed by how well he interpreted my song 'Who'd Have Known'.
"The ironic thing about this was that I had re-worked Take That's 'Shine' by writing a Brand New lyric to their song - which became 'Who'd Have Known'.
"So Take That's original song continues to have legs by being re-written, twice over."