Who Is This Bieber Defeater, This Esperanza Spalding?

Who is this woman who dare defeat tween heartthrob Justin Bieber in musical competition, sending shivers of dread through the hearts of his millions of pre-pubescent female followers?

Why she is Esperanza Spalding.

And it turns out Spalding, who was named Best Newcomer at Sunday's Grammy Awards, has performed for President Barack Obama, with jazz legends like Herbie Hancock, and before thousands of eager Prince fans.

The 26-year-old Portland, Ore., native became the first jazz artist to win the award in a stunner that saw her defeat Mumford & Sons, Florence and the Machine, rapper Drake, and the heavy favorite, teen pop phenom Justin Bieber.

"I feel really lucky that I got to be acknowledged on this stage in front of so many people who hopefully will get to experience my music, and I got there by doing what's really dear to my heart," said Spalding backstage after her win.

You could say Spalding is the jazz world's Bieber: a young sensation who has been a top-seller in the genre, and with amazing hair, usually worn in a huge Afro. Her talents are deep: she's also a multi-instrumentalist, songwriter, producer and arranger; was the youngest instructor at the renowned Berklee College of Music; and counts Prince as one of her musical mentors -- not to mention that White House concert.

Her latest album, "Chamber Music Society," blended her classical background with her jazz material. She had hoped for a nomination in the jazz categories and was surprised to be nominated for best new artist instead.

Things were still surreal for her after her big win: "It's already weird that I'm here, sitting in front of you," she told reporters backstage.

Spalding said her Grammy win was just the beginning in what she hoped would be a rich, long career in jazz.

"In the world I come from, this is the beginning of the beginning. I'm 26 ... people (in jazz) are more older than me, and they're still ascending," she said.

Which may be another thing she has in common with Bieber, with whom she hung out backstage after her win.

"He has great hair, and I have great hair!" she joked.

- The Associated Press contributed to this report.