Christina Aguilera and Demi Lovato deliver powerhouse Billboard vocals | ABS US DAILY NEWS

They're two of the world's biggest powerhouse vocalists. And Christina Aguilera, 37, and Demi Lovato, 25, sure didn't disappoint when they took to the stage at the 2018 Billboard Awards on Sunday night. Debuting their new duet Fall In Line, the women brought the house down.  Beginning the track solo, Christina appeared in a shiny black trench coat with a belt around her waist. She added knee-high boots and had her short blonde locks styled into loose waves. The beauty started the soulful vocal while being surrounded by dancers dressed as soldiers.Demi entered for the second verse and was also seen wearing black latex.She opted for a zip-up jacket and matching pants. The Sorry Not Sorry songstress also kept her hair out in a wet look style.  Demi and Christina then went on to serve an immaculate vocal duet.The performance ended with video clips of young girls holding flowers and laying in the grass. The track is part of Christina's upcoming eighth album Liberation.