The annual celebration of the biggest chart-topping stars in music was full of big wins, performances and on stage antics.

Here are 7 of the buzziest moments that had everyone talking.

The pop star who's been busy freaking out parents for the past four years with overly sexualized videos, stage antics and outfits returned to form on Sunday night with a widely praised performance of her latest single.

She has been open that it's a love song written about her fiancé Liam Hemsworth ("Hunger Games"), and her love for him seemed to be on full display as she choked up at the end of the song while singing, "I wanna thank you with all of my heart/It's a brand new start/A dream come true/In Malibu."

The emotional performance sparked a personalized trending Twitter hashtag #Mileybu, and lots of tears from fans.

Who are they? Where did they come from? How'd they beat Instagram queen Selena Gomez?!

Admittedly, we only know the basics about these guys: BTS is a 7-member K-pop boy band from South Korea. They landed atop Billboard's Social 50 chart last October, and remained there for 25 weeks. In March 2016, Forbes declared the group to be the single most retweeted artist on Twitter, which even honored the group with the first-ever K-pop Twitter emoji.

The group just beat out Gomez, Justin Bieber, Shawn Mendes, Ariana Grande to take home their first Billboard Music Award, and even got a nod of approval from Miley Cyrus when they said, "This award belongs to the every people all around the world that shine their love and light on us by the millions."

Their win instantly made #BTS a top-trending hashtag on Twitter as fans, like this one below, shared their excitement.

The actress and singer co-hosted the show with Ludacris, but she's soaking up all of the spotlight.

Her name has been mentioned in over 46,000 tweets and counting since the show kicked off on Sunday. Not only did she wow fans by singing Celine Dion at her co-host's request, but she effectively captured the joy music brings us all -- famous or not -- while dancing to Cher and even got a shoutout by Drake, who said, "Vanessa Hudgens, you look incredible tonight," much to the displeasure of Nicki Minaj, who was openly pouting on camera when the show cut to her sour reaction.

"Excuse me? What about me?" Minaj was spotted saying. (Drake did eventually give Minaj her own shoutout, which put a smile back on her face.)

Drake, named Top Artist of the Year, wasn't just a charmer on stage, he was the biggest winner of the night, winning in 13 of the 22 categories he was nominated in, which tops Adele's old record of most Billboard awards in a single night. Other big wins for the rapper include Top Male Artist, Top Billboard 200 artist and Top Hot 100 artist.

The hip-hop star also squashed a beef with Ludacris while accepting an award, and performed his song "Gyalchester" inside the famed Bellagio Fountains, a regular Vegas tourist attraction because of its light show.

The iconic singer performed everyone's favorite middle school dance song, "My Heart Will Go On," in honor of the 20th anniversary of "Titanic." As you can guess, she slayed, because that's what a performer of her caliber does every time she hits the stage. Whether or not it was the designer's intention, her glamorous white gown made her appear as if she was an angel gift wrapped for humanity's enjoyment.

The superstar who might just end up succeeding Michael Jackson as the next King of Pop managed to wow the Billboard audience without even stepping foot in Las Vegas. He appeared as a hologram as he sang “Versace on the Floor” live from his 24K Magic World Tour in Amsterdam.

Cher won the Icon Award, and gave a humble acceptance speech, citing "luck" as the biggest contributor to her success, but anyone who watched her perform "Believe" and "If I Could Turn Back Time" was probably a little skeptical of her analysis of her 53-year career, because she crushed it like it was 1989. Viewers watching her strut around stage in black leather and fishnet stockings may have also been surprised to hear she is 71.

That's right, this woman who looks about as youthful as Gwen Stefani, is a senior citizen. Could have fooled us.