It included the cast reminiscing about their time on the show as well as cameos from A-list fans.
And one of those fans managed to make his way onto the Central Perk set, Jennifer’s photos have revealed.
Jen posted another picture of her taking a selfie in the coffee house with her castmates, while a third saw her posing with director James Burrows.
She wrote: “Still basking in all the love from the #FriendsReunion. Thank you each and every one of you.
“Swipe for… The bazillionth selfie taken with the five of us… When two TOTALLY different worlds collide – @_schwim_’s face says it all.”
Justin appeared during the special, strutting his stuff during a Friends-themed fashion show.
Elsewhere, Lady Gaga performed the show’s famous song Smelly Cat alongside Lisa Kudrow, while David Beckham and K-pop stars BTS also shared their special memories of the show.