A&M/Universal's Welsh vocalist Duffy added another dimension to her hugely successful U.K. launch yesterday (March 9), as her debut album, "Rockferry," opened at No. 1, while the single "Mercy" bagged a fourth week at the top.

Official U.K. Charts Company data shows that "Rockferry" is Britain's fastest-selling album of the year so far, with out-of-the-box sales of 180,000, more than the rest of the top 10 combined. Duffy's arrival pushed Amy Winehouse's "Back to Black -- The Deluxe Edition" (Universal Island) down to No. 2 as Nickelback's "All The Right Reasons" (Roadrunner) climbed back 6-3.

Nick Cave & the Bad Seeds entered at No. 4 with "Dig Lazarus Dig" (Mute) and further down the chart there were new entries for the Cardigans' "Best Of" (Stockholm/Universal) at No. 32 and Billy Bragg's "Mr. Love and Justice" (Cooking Vinyl) at No. 33.

On the singles chart, "Mercy" stayed at No. 1 in a top three that was unchanged for a third week, with "What's It Gonna Be" (Ministry of Sound) by H "Two" O featuring Platnum at No. 2 and Nickelback's "Rockstar" at No. 3. OneRepublic's "Stop and Stare" (Interscope) rose 8-4 and "Come On Girl" (4th & Broadway/Universal Island) by Taio Cruz featuring Luciana moved 11-5.

Also leaping into the top 10 were Danish pop band Alphabeat's "Fascination" (Charisma/EMI), which cruised 23-7; Westlife's "Us Against the World" (S/Sony BMG), which motored 40-8; and "Low" (Atlantic/Warner Bros.) by Flo Rida featuring Luciana, which inched up 12-9.

On Billboard's European charts, Winehouse scored a second consecutive and ninth aggregate week at the helm of European Top 100 Albums with "Back to Black," while "Apologize" (Mosley/Blackground/Interscope) by Timbaland presents OneRepublic resumed its supremacy on Eurochart Hot 100 Singles, scoring a 15th week in total at No. 1.