Grande also sang Timberlake's parts since he was wrapping up his "Man of the Woods" tour in CT and was unable to attend. Earlier in the week, Grande teased the upcoming appearance, posting videos of her singing along to the group's music.
The 30-year-old French singer was joined by several dancers during her set before she released red powder into the audience of fans.
Grande, who also performed her hit God Is a Woman, gave the quartet a huge introduction in saying, 'I've been waiting all my motherf***ing life to say this: *NSYNC!' Watch clips from her set below.
In October, Grande broke off her engagement to SNL performer Pete Davidson.
Diddy said Grande is "still standing" after a hard year.
Similar sound issues appeared to plague Diddy and Mase when they arrived to sing Mo Money Mo Problems, their 1999 smash with the Notorious B.I.G.
Grande has also recently been open about her struggles with PTSD following the suicide bombing that killed 22 people at her concert in Manchester, United Kingdom, in May 2017. "She's been through a whole lot, but she's still standing", he said.