The "Boyfriend" singer dropped in as a surprise guest during Streisand's concert performance at the United Center in Chicago Tuesday night, where they performed the famous duet "No More Tears (Enough Is Enough)," with Grande admirably taking on the part originated by Donna Summer.
Streisand took to social media to share a snapshot of herself and Grande standing side by side in the green room before the show, which the songstress captioned, "Secret’s out. Thank you @arianagrande."
Grande commented on the beaming photo, "I’m sobbing 🖤 love you so much. i cant. get over this. it’s just.... the most special and cherished experience ever. thank you."
Grande later shared the same photo, on in black and white, to Twitter, writing in the caption, "cherishing this moment forever @BarbraStreisand."
During the performance, Grande took the stage in a black suit, which mirrored Streisand's all-black ensemble, and the pair held hands while performing the iconic duet.
The audience immediately gave Grande a standing ovation as she took the stage, and many excited fans snapped photos of the performance.
The team-up came one day after Streisand teased the possibility of a collaboration by sharing a semi-cryptic snapshot to Instagram that was just a close-up of her well-manicured hands next to Grande's hand -- including signature finger tattoos and sweater sleeve.
"Made a new friend…" Streisand said, without mentioning Grande by name. However, the singer commented on the pic with a simple heart emoji.