It's her second award of the night
The star picked up her award from presenter Alex James.
“Oh my gosh! I’m starting to recognise your faces. I don’t mean to be greedy and take home another award,” the singer joked, before thanking her fans.
The acts nominated for Best British Breakthrough Act were:
The Last Shadow Puppets
Scouting For Girls
The Ting Tings
Keep checking NME.COM throughout the evening for the latest from the BRIT Awards 2009.
For more stories and the results from the 2009 BRIT Awards
head to NME.COM‘s BRIT Award index now.