Charli XCX Performs ‘Boom Clap’ and ‘Break the Rules’ at the 2014 American Music Awards [VIDEO]

Charli XCX totally stunned audiences at the 2014 American Music Awards, performing hit songs 'Boom Clap' and 'Break The Rules.' The ever dapper Ansel Elgort introduced Charli’s performance — which was pretty appropriate, considering her hit song ‘Boom Clap’ was on the soundtrack for ‘The Fault In Our Stars.'

Charli's outfit was straight out of the '90s -- a frilly, light blue prom dress and red sunglasses. Her entire backing band (all women, by the way — go girl power!) was also dressed in floor-length prom dresses while they played one of our favorite tracks of the year, 'Boom Clap.'

But then Charli ripped off her prom dress and glasses, revealing a super sexy black latex bustier and mini-skirt combo and totally smoked-out eyeshadow. She started in on 'Break the Rules' and her performance quickly turned into the anarchist high school set of our dreams.

She then proceeded to totally destroy her own set as the rest of the world looked on in awe. Let us assure you -- it was just as cool as it sounds.

See Photos of the 2014 American Music Awards Red Carpet