As if anyone underestimated the power of Fox's "American Idol," winner Kelly Clarkson has scored a massive hit with her first single, selling in excess of 236,000 copies in its first week, according to SoundScan.

That means the double A-side single, "Before Your Love/A Moment Like This," will easily settle into the No. 1 spot atop next week's Billboard singles chart.

Clarkson's closest rival was Nivea's "Don't Mess With My Man" -- which came in an extremely distant No. 2, selling 4,955 copies.

MTV News reports that the debut of the Texas-born Clarkson, 20, was so enormous that it outsold all of the other top 20 singles, which had combined sales of just 34,331. Clarkson's song was No. 1 in every market, said Aaron Borns, director of marketing for Clarkson's label, RCA Records. (Sales of the track were strongest in Dallas and New York.)

"It's fantastic," Burns tells MTV. "The sales were so strong early in the week that we expected to see very big numbers, but this is one of the biggest singles anyone has had in years."

The single is moving at the rate of more than 250 copies sold per day at the Wal-Mart in Clarkson's hometown of Burleson, Texas, according to assistant manager Pedro Rodriguez. As he told MTV, "People are coming in to buy it because they know her and because they want to support a local girl."