British star Estelle has held firm at the top of the singles chart with American Boy, featuring Kanye West.
But there's a new number two - Low by Flo Rida featuring T-Pain - which knocked Duffy's former number one, Mercy, down to three.
High-climber Black and Gold by Sam Sparrow leapt from 23 to four. Madonna's track with Justin Timberlake - 4 Minutes - made up the top five.
In the album chart, Duffy retained the top spot with her release, Rockferry.
Panic at the Disco's Pretty Odd stormed straight to two and Oxford's Foals were also a new entry - at number three with Antidotes.