Though his debut album,  In the Lonely Hour, just dropped yesterday, British soul singer Sam Smith is already poised to conquer America.

The 22-year-old out crooner is currently MTV's Artist to Watch—and he's already appeared on SNL, won numerous awards in the UK, and recorded a duet version of his single "Stay with Me" with the legendary Mary J. Blige.

No mean feat for a guy who was cleaning out toilets in a London bar two years ago.

Last night, Blige surprised fans who came to see Smith perform at a special show at New York's legendary Apollo Theater—joining him on stage to sing "Stay," which was ironically the show's closer.

The New York Times paints a picture of the amazing evening:

For the young British soul singer Sam Smith, the Apollo was a sort of validation, maybe a homecoming, definitely a dream fulfilled. For just over an hour on Tuesday — the same day his debut album, “In the Lonely Hour” (Capitol), was released — he treated the venue as something priceless, and in turn gave the stage the sort of meaning it once had night in and night out...

At the encore, the R&B titan Mary J. Blige quietly came out onstage to reprise her duet with him, “Stay With Me,” a face-off in which Mr. Smith, ceding his stage to his guest, chose awe over pride, and Ms. Blige respectfully tried not to out-emote her host. Like the Apollo, Ms. Blige is a symbol for Mr. Smith, and given the opportunity to see her up close, he embraced it tentatively and with care. In return, she nourished him.

Smith won't have Blige with him when he launches his North American tour in September, but anyone able to make one of his shows should consider themselves blessed nonetheless.

Still, as amazing as his voice is—and it's damn near angelic—Smith's charm, humility and honesty on stage are equally seductive. "I've never been in a relationship," he confessed to the audience Tuesday night, before challenging the idea that you had to have been in one to write about love. (Stephen Sondheim sure didn't think so.)

Earlier this month, Smith told The Fader that In the Lonely Hour was mostly inspired by his feelings for a man who didn't love him back. "I think I'm over it now, but I was in a very dark place. I kept feeling lonely in the fact that I hadn't felt love before."

We feel love for Sam Smith—and its clear the feeling is mutual.

Below, watch Sam Smith and Mary J. Blige perform their version of "Stay with Me"