The 'I Want You Back' hitmakers - also featuring Chris Kirkpatrick, Joey Fatone, JC Chasez and Lance Bass - came together for Justin's 'One Night Show' at the Wiltern in Los Angeles on Wednesday night (13.03.24).
The iconic boy band came together to perform 1990s classics 'Bye Bye Bye' and 'It's Gonna Be Me'.
They also treated fans to the live debut of new song 'Paradise', which features on his upcoming album 'Everything I Thought It Was', which drops on Friday (15.03.24).
The track is the second *NSYNC have worked on together in recent memory, after 'Better Place' last year for the 'Trolls Band Together soundtrack', which marked their first song in over two decades.
Before this week, the group hadn't performed on stage together since reuniting when JT won the Video Vanguard Award at the 2013 MTV Video Music Awards.
Five years later, they appeared publicly together to receive their star on the Hollywood Walk of Fame, but fans had to wait until last year's MTV VMAs to see them reunite in public again.
They came together that night to present the best pop prize to Taylor Swift.
While he hadn't worked with NSYNC in over 20 years, the 'SexyBack' hitmaker admitted it felt like no time had passed when they got together again to record 'Better Place'.
Speaking on 'The Kelly Clarkson Show', he said: "That was fun. It's kind of crazy, like, there's so much that just picks up right where it left off as far as the chemistry."
And Lance had "no idea" there would be such a demand for the group to make a comeback.
He told 'Entertainment Tonight': "It is beautiful, you know? To be this age and the fans are still this excited, it is a dream come true.
"I had no idea the fandom would go this nuts. It was pretty emotional, the first time we all got in the studio together.
"Back in March, we decided to, you know, get back together and have some fun and it was like no [time] had passed."
"But there was there was a lot of tears. It was just tears of joy. And it was just a beautiful moment.
"Like, time does so much and for us to finally be together, it just feels right."