Reading her acceptance speech for top new artist from her smart phone, Lorde noted her meteoric rise started with Royals, a song she wrote when she was 15.
"I'm 17 and a half now and I'm so thankful to have had the opportunity to grow and learn as a new artist in the spotlight at this time.
"I am thankful for the dialogue around my work and myself and I am thankful to be around such talented new artists.''
Some people on Twitter questioned whether Lorde should have qualified for top rock song, but it spent several weeks at the top of Billboard's US Hot Rock Songs chart.
She performed her New Zealand number one song Tennis Court shortly after winning her second award.
Three of the awards Lorde was nominated for - hot 100 song, digital song and radio song - went to Robin Thicke for his hit Blurred Lines, while Imagine Dragons beat her to four awards - hot 100 artist, rock album, rock artist and streaming song (audio).
Katy Perry beat her to top female artist and top digital songs artist, while Justin Timberlake headed her to win top radio songs artist.
Lorde earlier this year won Grammy awards for best pop solo performance and song of the year awards for Royals, sharing the song of the year award with co-writer and producer Joel Little.
Watch Lorde perform Tennis Court here:
A FULL LIST OF WINNERS FROM THE BILLBOARD MUSIC AWARDS:
Top Artist: Justin Timberlake
Top New Artist: Lorde
Top Male Artist: Justin Timberlake
Top Female Artist: Katy Perry
Top Duo/Group: Imagine Dragons
Top Billboard 200 Artist: Justin Timberlake
Top Hot 100 Artist: Imagine Dragons
Top Digital Songs Artist: Katy Perry
Top Radio Songs Artist: Justin Timberlake
Top Touring Artist: Bon Jovi
Top Social Artist: Justin Bieber
Top Streaming Artist: Miley Cyrus
Top R&B Artist: Justin Timberlake
Top Rap Artist: Eminem
Top Country Artist: Luke Bryan
Top Rock Artist: Imagine Dragons
Top Latin Artist: Marc Anthony
Top Dance/Electronic Artist: Daft Punk
Top Christian Artist: Chris Tomlin
Top Billboard 200 Album: Justin Timberlake, The 20/20 Experience
Top R&B Album: Justin Timberlake, The 20/20 Experience
Top Rap Album: Eminem, The Marshall Mathers LP 2
Top Country Album: Luke Bryan, Crash My Party
Top Rock Album: Imagine Dragons, Night Visions
Top Latin Album: Marc Anthony, 3.0
Top Dance/Electronic Album: Daft Punk, Random Access Memories
Top Christian Album: Alan Jackson, Precious Memories: Volume II
Top Hot 100 Song: Robin Thicke Featuring T.I. & Pharrell, Blurred Lines
Top Digital Song: Robin Thicke, Featuring T.I. & Pharrell, Blurred Lines
Top Radio Song: Robin Thicke Featuring T.I. & Pharrell, Blurred Lines
Top Streaming Song (Audio): Imagine Dragons, Radioactive
Top Streaming Song (Video): Miley Cyrus, Wrecking Ball
Top R&B Song: Robin Thicke Feat. T.I. & Pharrell, Blurred Lines
Top Rap Song: Macklemore & Ryan Lewis Featuring Ray Dalton, Can't Hold Us
Top Country Song: Florida Georgia Line Featuring Nelly, Cruise
Top Rock Song: Lorde, Royals
Top Latin Song: Marc Anthony, Vivir Mi Vida
Top Dance/Electronic Song: Avicii, Wake Me Up!
Top Christian Song: Matthew West, Hello, My Name Is
- AAP
