EXCLUSIVE: Justin Bieber Celebrates First-Ever GRAMMY Win With Sushi

Justin Bieber is clearly having the best Monday ever!

The 21-year-old popstar won his first GRAMMY award during the award show's portion that is held before the telecast.

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Bieber took home the gramophone for Best Dance Recording with Skrillex and Diplo for "Where Are U Now," and following the exciting news, the "Love Yourself" singer took to Twitter, retweeting a fan who screenshotted one of his tweets from December 31, 2010.

"#2011 the dream… would be to win a grammy," the original tweet posted by Bieber read. "That would be just amazing. A boy can dream right? #2011."

He quickly followed it up with an adorable fake acceptance video, saying, "You're putting me on the spot but I just want to say thank you to all the people who've supported me over the last couple years, but honestly I couldn't have done this without Scooter Braun."

"This is really Scooter's award,” he joked. "The reason why it's his is because it's an off-camera award, and if it was on-camera award, it'd be my award."

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An eyewitness tells ET that Bieber -- who's set to perform later on the GRAMMYs stage -- was across the street from the Staples Center in downtown Los Angeles, eating sushi at Katsuya when his win was announced.

While Bieber was grabbing grub, Skrillex and Diplo were there to accept the award for the trio.

"We didn't plan a speech, I'm bad at speeches but I wanted to make one more shout out to the mother fuckn man @poobear," Skrillex shared on Twitter. "And shout out every artist who was apart of the Jack U album." Diplo and Skrillex , who make up Jack Ü, also won for Best Dance/Electronic Album.

Diplo shared a photo of the two accepting the award, captioning it, "For all my haters."

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