Jessie J took the stage at the Roxy Theatre in LA last night for her first headlining gig in the US on Monday night (April 9). Spotted among the sold out crowd were the boys of The Wanted, as well as Jason DeRulo, who sported his bedazzled neck brace. The Brit singer sported a sassy ensemble of denim shorts, a Super Mario Brothers t-shirt, and earrings Nelly Furtado would certainly approve of. Jessie kicked off the night with "Who's Laughing Now" before diving into a Luther Vandross cover and a Bob Marley mashup of "One Love" and "Stand Up". And after making the audience turn around to dance with the person behind them, the "Laserlight" star closed out the night with a killer rendition of her hit single "Domino". Check out Jessie as she does it like no other.