Brandy and Monica had a very special guest drop in on their “Verzuz” battle on Monday night.

The webcast series from Swizz Beatz and Timbaland sees two artists pair up on Instagram Live to battle it out through 20 rounds with each contestant playing a hit and then receiving a rebuttal.

R&B icons Brandy and Monica have collaborated a number of times in the past, including on the massive hit “The Boy Is Mine”.

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Kamala Harris dropped by to kick off the battle by showing some love for the duo, and voicing support for Michelle Obama’s When We All Vote campaign, which is partnering with “Verzuz”.

“I just wanted to thank you ladies, you queens, you stars,” gushed the Democratic vice-presidential candidate, speaking via video link.

“Thank you for doing this for When We All Vote. It’s so important for everyone,” she continued. “You both used your voice in such a powerful way, and an extension of our voices is our vote.”

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“We understand the importance of people getting out and voting right now,” said Monica. “And they feel so helpless right now, but that’s how you help yourself, help your community, help your brothers and sisters.”

“I’m fangirling right now,” added Brandy.

Numerous celebrities tuned in to watch the battle, including Michelle Obama, Mariah Carey, Tiffany Haddish, and Zayn Malik, who were spotted in the chat.

Solange Knowles, Tyler the Creator, Babyface, Erykah Badu, Queen Latifah, Meek Mill, JoJo, Keke Palmer, Aubrey O’Day, Nas, Snoop Dogg, Fat Joe, Ashanti, Lil Jon, Miguel, Questlove, Lena Waithe, Omarion, Timbaland, Ne-Yo, Missy Elliott, Kehlani, Chloe x Halle, Dinah Jane, Juicy J, and Swizz Beatz also watched.

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Back in May, Monica made it clear that the battle would be a “celebration” because she didn’t want rumours resurfacing of a feud with Brandy.

“I understand the idea of [‘Verzuz’] and I think it’s really, really entertaining and it is an incredible idea,” Monica told V-103 as per Complex. “Now what I do like is it’s kind of turning into a celebration. I can handle a celebration. One thing that has happened to me my whole career is being put against someone else that I’m not even remotely similar to. I think the reality is, us being polar opposites makes it dope.”