Leona Lewis EXCLUSIVE: Star celebrates 15 years of Bleeding Love with Simon Cowell, Ryan Tedder and more

On December 16 2006, former receptionist Leona Lewis was catapulted to stardom as she was crowned the winner of the second series of The X Factor. Bagging herself a record deal under Simon Cowell's mentorship, London-born Leona had everything to prove. Could she transcend her TV talent show beginnings to become a bona fide recording artist?

If she were to succeed, she'd need a huge hit to springboard her career. A song to establish her artistic position and silence a press all-too-eager to brand her a one-hit wonder.

Enter: Bleeding Love.

Written by OneRepublic's Ryan Tedder, Leona's first original release was true lightning in a bottle stuff. A power ballad for the noughties, with its haunting organ intro, marching drums and inimitable vocal performance, Bleeding Love debuted at Number 1 on the Official Singles Chart in November 2007.

The track spent a total of seven weeks atop the chart, and has shifted over 2 million chart units in the UK to date; including 112 million UK streams and counting.

Now, Leona celebrates the timeless track's 15-year anniversary alongside Simon Cowell, Ryan Tedder and record producer Clive Davis in an exclusive mini documentary.

MORE: See Leona's Official Charts history in full

Speaking in the documentary, Leona explains: "Coming off The X Factor and having time to really delve into my music and bring that to life was really incredible for me. I got to work with some amazing producers that I'd dreamed of working with, so it was really such a life-changing moment for me.

"I knew that it was a song that I wanted to be a part of, so I took it, worked on it and interpreted it how I would sing it. I fell in love with it."

Simon Cowell adds: "It's one of the best moments I've ever experienced during my career. That song is going to be a hit in a hundred years time. It'll never, ever, ever be a bad song."

Songwriter Ryan Tedder also details its enduring success, saying: "Everywhere I go, I still hear it. From Hong Kong to South Africa, I hear Bleeding Love...Leona's a world class artist and a world class voice that's unique. When the song came out, nobody had heard anything like that type of song."

WATCH Leona Lewis's 15 years of Bleeding Love documentary below: