EDM duo Disclosure kicked off their arena tour in Los Angeles on Tuesday, and closed the show out in spectacular style when Sam Smith took the stage.
Smith, who was looking as svelte and stylish as ever, performed both of his collaborations with Disclosure -- "Latch" and "Omen" -- to the roar of a delighted crowd.
WATCH: Sam Smith Confirms He's Singing the James Bond 'Spectre' Theme Song!
While Disclosure has also collaborated with Lorde and The Weeknd, Smith was the night's biggest special guest. But the whole evening was a star-studded affair. The American Express UNSTAGED show, which was executive produced by James Corden, featured a surprise appearance by Lion Babe with Talib Kwel opening for the EDM duo.
Also, it's clear that the exercise and diet routine Smith's been on has been working great, as he's shown off on Instagram in recent weeks.
WATCH: Sam Smith Is the Skinniest We've Ever Seen Him, Shows Off a Wicked Sunburn
Recently, Smith released a new, brooding theme song for the upcoming James Bond film, Spectre, titled "Writing's On the Wall."
Check out the video below to hear a bit of the new track and find out why Smith is a little nervous for fans to listen to the new tune.