This may have been the finale performance that sealed the deal for Underwood, whom Idol judge Simon Cowell once predicted would not only win the competition, but would go on to "sell more records than any other previous Idol winners." (To see the emotional moment that Underwood learned she had won and tearfully performed, watch the video at the top of this post.)
Well, Cowell was right. According to Forbes, Underwood has been the top-earning Idol alum for two consecutive years now -- beating out Kelly Clarkson, Scotty McCreery and Adam Lambert for the top slot.
And 10 years after her big win, Underwood has released five studio albums -- her latest, Storyteller, is out now -- she's won seven GRAMMYs, 11 ACM Awards and, just this year, welcomed her first child with hubby Mike Fisher.
Not to mention -- the 32-year-old looks and sounds even better now than she did back then.
Underwood has lots to celebrate this week as Storyteller hits shelves and she gears up for one of her favorite holidays: Halloween! Find out how she's prepping in the video below.