Justin Bieber and Jaden Smith made their fans incredibly happy – and tearful and emotional – as they reunited on stage on Tuesday evening to perform their hit single Never Say Never.

Justin, 22, was in the midst of his Purpose tour show at Madison Square Garden in New York when 18-year-old music star and actor Jaden rocked out on to the stage to do his famous rap.

Fans were left going wild as the pair – who last performed at the iconic venue six years ago – put on a perfect rendition of their catchy tune.

One Belieber, known as lovelivejbieber on the social networking site, shared a video clip on Twitter of the beautiful moment, revealing that she was “crying” at the experience.

Following the emotional reunion, Justin posted a snap of the two of them hugging against a backdrop of overwhelmed fans on Instagram.

“Love you brother man,” the sentimental star wrote with the picture.

Justin Bieber and Jaden Smith in 2011Justin Bieber and Jaden Smith also performed Never Say Never at the 53rd Annual Grammy Awards back in 2011 (Matt Sayles/ AP/PA)

The comparison between the two talented stars between their last live duet at Madison Square Garden in 2010, and their most recent duet is astounding, each having grown up almost beyond recognition.

Justin was 16 at the time, and Jaden – the son of Will Smith and Jada Pinkett Smith – was a fresh-faced 12-year-old.

They’ve worked together several times over the years, but they’ve not appeared on the MSG stage since their memorable 2010 gig: it’s no surprise their admirers became sentimental.

Somewhat unsurprisingly, fans of the pair got quite emotional at their MSG reunion, many taking to Twitter to express their gratitude and other feelings.