Taylor Swift dominated the Billboard Music Awards with eight wins, including top artist, while Kanye West was booed during his performance that closed the three-hour event.
Swift also won top Billboard 200 album for "1989" and top female artist Sunday night.
"Oh, this is such a good night!" she said after winning the top prize, besting One Direction, Ariana Grande, Sam Smith and Katy Perry. "Early this morning I watched my brother Austin graduate from Notre Dame ... (and) to anyone who's graduating this year ... this is for you."
West, however, was booed during his smoky performance of "All Day" and "Black Skinhead."
"And now a doctor," Kylie Jenner said while introducing the rapper, who earned an honorary doctorate from the Art Institute of Chicago last week.
Swift owned the night with wins for top Hot 100 artist and the fan-voted artist achievement award. Swift kissed her rumored boyfriend Calvin Harris on the cheek and gave him a hug at the MGM Grand Garden Arena in Las Vegas.
Swift, who sat next to the DJ-producer-singer, kicked off the awards by debuting her action-filled music video for "Bad Blood," which stars Selena Gomez and Lena Dunham and showcases Swift as a fighting vixen.
The video opened with Swift and Gomez fighting men in an office and then fighting each other. It ended with Swift's and Gomez's armies going head to head. Other stars in the clip included Mariska Hargitay, Ellen Pompeo, Jessica Alba and Ellie Goulding, and Hayley Williams of Paramore.
Swift swapped her first two verses with new ones from rapper Kendrick Lamar for "Bad Blood," a song rumored to be about Swift's friendship with Perry.
"I am so excited I got to show the world," Swift told the audience.
One Direction, which recently downsized to four members, won the night's first award for top duo/group. They also won top touring artist.
"There is one more person to share this with, and that's our brother Zayn," Liam Payne said of Zayn Malik, who left the boy band. Iggy Azalea won top rap song for "Fancy" as her NBA player boyfriend, Nick Young, watched her with emotion.
Azalea also won top streaming artist and rap artist. Like Azalea, Smith and Pharrell also won three awards — the most after Swift.
Smith, who recently had vocal surgery, didn't attend the show. He wrote his thank you speech on cue cards, which aired via video when he won top male artist.