Just weeks after Floyd Mayweather and Manny Pacquiao faced off for boxing’s biggest fight, the hottest stars of the music world met in the same arena to compete for the Billboard Music Awards.

It was a glittering show at the MGM Grand Garden Arena in Las Vegas, where Taylor Swift was the biggest winner.

Here are the must-see moments of the night.

Taylor snuggles up to Calvin Harris.

Taylor Swift, right, hugs Calvin Harris
Taylor Swift, right, hugs Calvin Harris after winning the album gong for “1989 at the Billboard Music Awards (Chris Pizzello/Invision/AP)

Tay-Tay sat in the front row next to the Scottish DJ and the pair kissed and cuddled throughout the evening, especially when he congratulated her as her name was called again and again from the stage.

One Direction shout out to Zayn.

One Direction
Louis Tomlinson, Niall Horan, Harry Styles and Liam Payne of One Direction accept the award for top duo/group (Chris Pizzello/Invision/AP)

One Direction were the first winners of the night, scoring the top duo/group award and they paid tribute to their former band mate. Zayn Malik left the band in March and Liam Payne put aside rumoured of animosity as he dedicated their gong to “our brother, Zayn”.

Kanye blends old and new.

Kanye West
Kanye West performs at the Billboard Music Awards (Chris Pizzello/Invision)

Kanye West performed new single All Day and old hit Black Skinhead in silhouette on an elevated platform behind glittering pyrotechnic effects. The American TV censors killed the audio for the rude words but the fact he could close a show with a 2013 song showed the crowd who was boss.

Britney and Iggy throw it back.

Britney and Iggy
Iggy Azalea and Britney Spears arrive at the Billboard Music Awards at the MGM Grand Garden Arena (Eric Jamison/Invision/AP)

Britney Spears and Iggy Azalea performed their single Pretty Girls with a distinctly retro twist.

Dancers were dressed in 90s neon and Britney sported a latex and sheer mesh catsuit whole Aussie rapper Iggy donned a silver mini skirt and crop top.

Taylor brings her Bad Blood pals.

Zendaya, from left, Martha Hunt, Taylor Swift, Lily Aldridge, Hailee Steinfeld, and Ellen Pompeo
Zendaya, Martha Hunt, Taylor Swift, Lily Aldridge, Hailee Steinfeld and Ellen Pompeo speak at the Billboard Music Awards (Chris Pizzello/Invision)

The show opened with the hotly anticipated debut of Taylor Swift’s new video for Bad Blood.

The video was met with deafening screams in the MGM before Taylor appeared on stage with some of the stars of the action-packed mini-movie.

She was joined by Lily Aldridge, Ellen Pompeo, Hailee Steinfeld and Zendaya on stage right after the premiere to introduce the first performer of the night, Van Halen.

Mariah is the new queen of Vegas.

Mariah Carey
Mariah Carey on stage at the Billboard Music Awards (Chris Pizzello/Invision/AP)

Mariah Carey has just begun a residency at Caesars Palace and she marked her arrival with an impressive performance of old and new hits. Dressed in a nude sequinned gown she opened her performance with 90s single Vision Of Love and moved into her newest offering Infinity.

Simple Minds and Molly mark 30 years.

Molly Ringwald
Molly Ringwald introduces a performance by Simple Minds (Chris Pizzello/Invision/AP)

It has been 30 years since The Breakfast Club was in cinemas and there was a surprise treat for fans of both the movie and the hit song from the soundtrack.

Simple Minds
James Kerr of Simple Minds performs a tribute to the 30th anniversary of The Breakfast Club (Chris Pizzello/AP)

The film’s star Molly Ringwald introduced Simple Minds, who performed Don’t You (Forget About Me).

She also used her moment on stage to tell Taylor Swift she wanted to be part of her club and her dream came true when she was spotted dancing with Tay in the front row as the band rocked out.