The Welsh chanteuse won Best Female, Best Album and Best British Breakthrough Act for her debut album, "Rockferry."
Despite four nominations, Coldplay walked away without any trophies. Like-minded rock band Elbow won Best British Group, and pop quintet Girls Aloud notched Best Single for "The Promise."
Related Content from AccessHollywood.com:
VIEW THE PHOTOS: Duffy
PLAY IT NOW: 2009 Grammy Awards Arrivals: Adele Talks Grammy Win
PLAY IT NOW: Music Video: Duffy - 'Mercy'