British soul sensation Sam Smith delighted fans at the Apollo Theater in New York on Tuesday night (17Jun14) when he was joined onstage by his idol Mary J. Blige.

The singer celebrated the U.S. release of his debut album, In the Lonely Hour, by performing at the hallowed Harlem concert venue, backed by a live band with a four-piece string section.

And he sent fans into a frenzy during his encore as Blige stepped out to join the music newcomer in the spotlight for a rendition of their new duet, Stay With Me.

He took to his blog early on Wednesday (18Jun14) to gush about the special gig, writing, "Last night was one of the greatest moments of my life. I love you @maryjblige".

Responding to his tweet, Blige wrote, "I love you too. U R (sic) Amazing & Anointed."

In the Lonely Hour became the U.K.'s fastest selling album of 2014 when it charted at number one on 1 June (14). The album was released in the U.S. on Tuesday and is also expected to chart high in the Billboard 200 next week (25Jun14).