Billie Eilish has become the first artist since 1981 to win the "Big Four" trophies at the Grammy Music Awards.
The 18-year-old singer won best new artist, song, record and album for her single Bad Guy and her debut album When We All Fall Asleep, Where Do We Go?
She thanked fellow artist Ariana Grande on stage when accepting her award for album of the year.
"I think Ariana deserves this... I love you, thank you for this," she said.
Eilish made her Grammy debut alongside her older brother and music producer Finneas McConnell, who said he was surprised by the win.
He said: "We wrote an album about depression and suicidal thoughts and climate change."
Christopher Cross was the last artist to win all four major awards back in 1981.
Eilish denied fellow singer Lizzo, who had been expected to win some of the major awards, success, although she scored gongs in some of the lesser categories - best pop solo performance, best urban contemporary album and best traditional R&B performance.
Lil Nas X also scored two Grammys for best music video for Old Town Road and best pop duo/group performance.
The night saw stand-out performances from Eilish, Grande and Camila Cabello.
Eilish made her live Grammy debut alongside her brother and songwriter O'Connell, perching on a stool as she performed the piano ballad When The Party's Over.
Cabello reduced her father to tears with a heartfelt performance of First Man, a song about their relationship.
One of the many who lost out to Eilish was Lewis Capaldi who also nearly lost his seat.
The Scottish singer, who was nominated for the Song of the Year award for his hit single Someone You Loved, suffered a case of mistaken identity and was thought to be a seat-filler rather than one of the invited guests.
He wrote on Twitter: "A lady at the grammys has just come up and offered to take my seat because she thought I was one of the people who sits in the chairs to fill them when someone gets up to use the bathroom."
He added a string of crying laughing emojis.
The night was overshadowed by the news of the death of Kobe Bryant, and many artists paid tribute to the basketball legend on stage.
Host Alicia Keys said: "We're all feeling crazy sadness right now... because earlier today in Los Angeles, America, the whole world lost a hero."
"We never imagined in a million years that we'd have to start the show like this."
The event took place in Los Angeles' Staples Centre, the home stadium of The Lakers where Bryant played for 20 years.