Billboard's Most Powerful MinorsWho Did Justin Bieber Lose Top Spot To?

A 17-year-old singer from New Zealand takes the lead, who is she?

1. Lorde

New Zealand native Lorde beats Australian pop band 5 Seconds of Summer and wild child Justin Bieber into second and third place respectively to be named Billboard's hottest star under 21, topping the magazine's annual ranking of Music's Most Powerful Minors.

The 17-year-old singer isn't old enough to vote but already has two Grammys below her belt thanks to her big hit - Royals - released last year.

The publication hailed the list as 'perhaps the most impressive crop of under-21 stars,' it had ever assembled.

Billboard said: 'These 21 artists have already accomplished a great deal, but are safe bets to continue finding success as they edge toward adulthood... For now they're just kids, but they're the kids that everyone in music is watching.'

Here is the full list of Billboard's Most Powerful Minors 2014:

2. 5 Seconds of Summer

3. Justin Bieber

4. Martin Garrix

5. Fifth Harmony

6. Austin Mahone

7. Earl Sweatshirt

8. Shawn Mendes

9. Becky G.

10. Chief Keef

11. Luis Coronel

12. Meghan Trainor

13. Cody Simpson

14. Madeon

15. Bobby Shmurda

16. Scotty McCreery

17. Troye Sivan

18. Rae Sremmurd

19. Akdong Musician

20. The Vamps

21. Unlocking The Truth

To also mark the publication of the list, Billboard also compiled a chart of the 21 biggest hits from the past 21 years by artists who were under 21 at the time.

Topping the song list was LeAnn Rimes' hit 'How Do I Live', which was released in 1997 when the star was just 15 years old.

Mario's 'Let Me Love You' - released when he was 21 in 2005 - took second place.

Lorde's 'Royals' came in third, Brandy & Monica's 'The Boy is Mine' was fourth and Usher's 'You Make Me Wanna' completed the top five.