The mom-of-one wore a black Balmain bodice (hello, cleavage!) with a pair of flowing black pants which she accessorized with huge diamond drop earrings and fake-fur drape as she arrived at the venue in Inglewood, California, to watch the British singer's show.
The reality TV star shared a series of pictures of her and her sisters enjoying the evening, and posing with model Cara Delevingne, who was also at the popular gig.
But while singer Smith was the evening's headliner, Kim's cleavage almost stole the show. The curvy TV star nearly popped out of her push-up bodice as she cuddled in with her sisters, Delevingne, and another female pal for a group picture while the concert went on in the background.
"Cause you're all I need," Kardashian captioned the shot, referencing Smith's lyrics.
Earlier in the evening, the Kardashian sisters went backstage and posed for more pictures, this time with Smith, who posed for photos with the entire Kardashian group, and a load of individual shots too.
Smith and the reality star previously met at Jimmy Kimmel's late-night show back in August 2014. After their meeting, the "Stay With Me" crooner gushed that she smelled of vanilla and was "really sweet" to him.
"I was sweating a little bit," he admitted to Capital FM. "She's beautiful and it was just really weird to meet someone like that who knows my music and is a fan of my music. It was really weird."
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