Carrie Underwood, who only a month ago became the fourth winner of "American Idol," now has country's top single with her "Inside Your Heaven."

The Desmond Child-written song, which Underwood performed during her final week of competition on the Fox series, debuts at No. 1 on The Billboard Hot 100.

Underwood is only the third artist to bow in the top slot since chart policy changed in 1998 to allow airplay-only tracks on the Hot 100, Billboard said.

Underwood's triumph follows in the footsteps of second season runner-up Clay Aiken's "This Is the Night" in 2003 and third-season winner Fantasia "I Believe" in 2004, the report said.

"Inside Your Heaven" also debuts at No. 1 on the Pop 100, where Gwen Stefani's "Hollaback Girl" falls to No. 4 after eight weeks on top.