After attending a charity benefit at a Studio City, Calif., bowling alley on Wednesday night, Brown made his way to the Emerson Theatre in Hollywood.
An eyewitness there tells E! News exclusively that around 1:20 a.m., Brown hopped up from his center table under the DJ booth and requested the mic to speak to the crowd. The DJ had Drake's song, "Started from the Bottom," cued up and Brown immediately told the DJ to stop playing the music. Addressing the crowd, Brown reportedly shouted out, "The DJ can play this s--t, but I want you all to know, F--k Drake!" and gave everyone the middle finger.
Brown then proceeded to have the DJ cut the music again and began freestyle rapping, our source says. He began with a full performance of "As You Were" and followed with "Turn Up the Music." What seemed to be a single performance turned into an all-out, full impromptu concert as he proceeded to sing "Beautiful People" and an additional five songs.
Football star Reggie Bush even ran up on stage to take the mic, acting as Brown's hype man.
The eyewitness added that before and after his impromptu performance, Brown was seen dressed in a Miami Hurricanes baseball jersey, drinking Ace of Spades Rose and ordering vodka all night. At one point, he ordered six bottles of rosé, costing $10,000, which came out in a gold sailboat. Brown had it sent over to football legend Michael Irvin, who was at Emerson celebrating his birthday
After getting pulled off the stage around 2 a.m., Brown proceeded to pull his orange hoodie up over his head and walked out to the song "Harlem Shake," the eyewitness noted. He was surrounded by an entourage that included several ladies.
Brown's rep could not be reached for comment.
Oh, and on a side note, Star Trek star Chris Pine was also spotted at the club.