Carrie Underwood couldn't help but gush about son Isaiah at the 2015 American Music Awards on Sunday.

The 32-year-old singer opened up about the 9-month-old in an interview with "Entertainment Tonight" on the red carpet. Underwood and husband Mike Fisher welcomed the infant in February, and the star confirmed she's loving motherhood.

"He's the best thing that me or my husband ever did -- he's amazing," she said. "At the end of the day, no matter what, I'm a mom. No matter how things go tonight -- if I win, if I lose, if I do great in my performance, if I don't -- I still get to go home to him."

"It just makes everything, I don't want to say less important because this is such an incredible night and I'm excited to be a part of it, but the mom card just trumps everything," she added.

Underwood beat Miranda Lambert and Kelsea Ballerini to win Favorite Country Female Artist, and performed her new single "Heartbeat." The song appears on her fifth studio album, Storyteller, which debuted at No. 2 on the Billboard 200.

Underwood and Fisher have been together since 2008, and married in July 2010.

The singer showed off her slim post-baby body on the November cover of Shape, telling the magazine she cut down on bread and took up hiking and boxing for exercise.