Haim have beaten off 14 other acts to win the BBC Sound of 2013 new music list.
These three Californian sisters have been compared to Fleetwood Mac and have already supported Florence and the Machine and Mumford and Sons.
The list, now in its 11th year, showcase the best new acts for the coming year and is compiled by 213 UK-based critics, broadcasters and bloggers.
Previous winners include Michael Kiwanuka, Jessie J, Adele, Mika, Ellie Goulding and Keane.
The top five acts for 2013 were:
• 1. Haim
• 2. AlunaGeorge
• 3. Angel Haze
• 4. Laura Mvula
• 5. Chvrches
BBC Radio 1 DJ Huw Stephens said Haim had a "contagious enthusiasm".
"Haim have an unapologetic passion for music that shines in their songs," he continued. "They're brilliant musicians who have a real talent for tunes that merge their tales of growing up in the 21st Century with a classic songwriting ability."
Este, Danielle and Alana Haim, who are aged between 21 and 26, started playing music as children when their parents enlisted them into a family covers band.
The sisters all play guitar, drums and sing and are still occasionally known to pull their mother and father on stage.
Haim's songs pay homage to feelgood, freewheeling '70s rock and anthemic '80s synth-pop, gaining a modern sheen by borrowing rhythms from contemporary R&B.
Previous Sound of... winners
• Sound of 2012: Michael Kiwanuka
• Sound of 2011: Jessie J
• Sound of 2010: Ellie Goulding
• Sound of 2009: Little Boots
• Sound of 2008: Adele
• Sound of 2007: Mika
• Sound of 2006: Corinne Bailey Rae
• Sound of 2005: The Bravery
• Sound of 2004: Keane
• Sound of 2003: 50 Cent
The longlist of the top 15 artists was published in December.
It is the first time that the top five acts have all been female or fronted by women.
Este Haim said: "It's the craziest thing to think we're on a list with so many amazing artists. This year the five bands that were in the list were all female fronted, right?
"We love the UK - the last time we were there, we were there for almost a month and a half. The UK is like a second home."
