Alicia Keys has stunned the U.S. album charts by claiming the number one spot after selling a staggering 742,000 copies of her new CD AS I AM in a week. The R+B star was expected to debut at number one, but even experts had no idea she'd crush her chart rivals. The figures give Keys the biggest album sales week by a female artist since Norah Jones' Feels Like Home smashed records with one million sales in 2004. Keys has also scored the highest opening sales week for a female artist in iTunes downloading history. Meanwhile, Josh Groban's festive album Noel shoots back up the new Billboard chart from six to two, while Celine Dion's Taking Chances debuts at three with a 214,000 sales week. Compilation Now 26 is new at four and Garth Brooks and the Eagles slide to five and six respectively. Reformed rock legends Led Zeppelin's two-disc retrospective, Mothership, debuts at seven, while last week's charttopper, JayZ's American Gangster, slips to eight.