She stole the hearts of the voting public after being crowned 'American Idol' during the wildly popular reality show's inaugural season, and now Kelly Clarkson is taking back the title of best-selling 'Idol' single of all-time, beating out country superstar Carrie Underwood.

Clarkson's 'Stronger (What Doesn't Kill You)' has dethroned Underwood's 'Before He Cheats,' but only by 1,000 copies -- Clarkson's hit has officially sold 3,510,000 to Underwood's 3,509,000 in single sales, the Hollywood Reporter reports. Still, even such a small margin means that officially, Kelly 'Crossover' Clarkson has the best-selling 'Idol' single ever.

Just last year, Clarkson, with help from country superstar Jason Aldean, claimed the title of best-selling country collaboration with the 2011 smash 'Don't You Wanna Stay,' which has sold more than 2.1 million downloads to date. Underwood and Brad Paisley follow close behind with a double platinum certification for their No. 1 duet, 'Remind Me.'

With two monster country collaborations under her belt, Clarkson is solidifying her presence in country music with 'Mr. Know It All,' the Texas native's first solo country single, which is spinning country-style nationwide. The kiss-off tune is likely to crack the Top 20 soon, as it is currently sitting at No. 23 on the Billboard charts. Off radio, she is dating Reba McEntire's stepson -- and Blake Shelton's manager -- Brandon Blackstock.