Justin Timberlake and former bandmates JC, Joey Fatone, Lance Bass and Chris Kirkpatrick treated fans to a 90s flashback as they performed two of their songs on Sunday night (25 August) in Brooklyn, New York.
Fans and celebrities alike went into a frenzy as the popular American boy band sang and danced their chart-topping hits, 'Girlfriend' and 'Bye Bye Bye' at the Barclays Centre, during Justin's solo performance.
Later, the boy band shared several behind-the-scenes snaps on their group Twitter account, which they created especially for their mini reunion.
The snaps show that the five-piece still have a close bond, despite not having shared a stage for a decade.
In one photo, Justin, who was awarded the prestigious 'Michael Jackson Video Vanguard Award' on the night, is seen joking around with his bandmates as they pulled funny expressions for a group photo.
Taking to Twitter, they said: "What a night! Thanks for all the support everyone. We love you so!"
Speaking about the performance yesterday (26 August), JC told Ryan Seacrest on his radio show, On Air with Ryan Seacrest: "Literally, two minutes after seeing everybody you feel like no time has passed."
He added: "Essentially everybody has remained the same and we all see each other at different times, but this was the first time we had a rehearsal together in 10 years, so everyone was going, 'Can we go through this one more time slowly?' So that part was pretty funny."
JC, who explained that 'N Sync's reunion was only "a matter of time" also said that it was "the worst kept secret ever".
'N Sync formed in Florida in 1995 and enjoyed a hugely successful pop career before parting ways in 2002, but when asked about a possible reunion tour, JC confirmed that it was just a one-off.
"No, it was just about five guys who were great friends who spent 10 or 15 years together touring and we wanted to give that back to our fans, but we were there mainly to support Justin," he added.
We hope they change their minds because we'd love to see the group back on stage again!
Would you love to see 'N Sync in a full blown reunion tour? Tell us below, as the best comment from across the website each week wins £50!
Why not take a look at 'N Sync's music video for 'Girlfriend' below: