Her performance of Uptown Funk was such a hit with the public that it forced Mark to release the track five weeks early.
The single which features vocals from follow url Bruno Mars, was originally due to drop on the 11th January.
Speaking to Newsbeat Fleur said: “Yeah I’m really sorry but all I can say is it’s props to all their creative hard work because it’s an amazing song.”
“I don’t know what they were thinking in their minds. I don’t think anyone expected my performance to be as popular as it was.”
Adding: “We didn’t expect it to go to number one on iTunes. That’s crazy like.”
And Mark Ronson gave a simple sarcastic…
I enjoy a good cover from time to time
— Mark Ronson (@MarkRonson) December 9, 2014
Double oops Fleur…