Billie Eilish swept the top Grammy categories on Sunday night, becoming the youngest (and only the second) artist in history to win the big four.

In their spectacular Grammys debut, Eilish, 18, and her brother/recording partner Finneas O’Connell, 22, took home six of the seven awards they were nominated for on Sunday.

Eilish won album of the year and pop vocal album (for “When We All Fall Asleep, Where Do We Go?”), record and song of the year (for “Bad Guy”) and new artist. She lost pop solo performance to Lizzo (for “Truth Hurts”), who was expected to have a much bigger night.

O’Connell nabbed engineered album (for “When We All Fall Asleep”) and producer of the year (both non-classical). He is a rare producer nominated for just one release (ordinarily producers are up for several), alongside Jack Antonoff (Taylor Swift, Lana Del Rey), Dan Auerbach (Black Keys, Yola), John Hill (Khalid, Cage the Elephant, Carly Rae Jepsen) and Ricky Reed (Lizzo, Maggie Rogers, Maren Morris).

Following a performance from Ariana Grande, the superstar siblings took the stage, delivering an emotional rendition of “When the Party’s Over,” a single featured on Eilish’s last album. Eilish captivated the room as she performed the ballad while perched on a stool. O’Connell, who played the piano alongside her, applauded his little sister as she closed the song.

They took the stage again after winning song of the year for “Bad Guy.” “I don’t even know what to say, I didn’t even think we’d win for this,” O’Connell said.

“Thank you,” Eilish and O’Connell said in a succinct speech at the end of the night after their record of the year win, which immediately preceded album of the year. “Can I just say that I think Ariana deserves this?” Eilish said during that acceptance speech.

“We didn’t write a speech for this because we didn’t make this album to win a Grammy,” O’Connell said. “We didn’t think it would win anything, ever. We wrote an album about depression and suicidal thoughts and climate change and being the bad guy — whatever that means. And we stand up here confused and grateful.”