Chris Brown threw the first punch in his brawl with Frank Ocean ... after Frank disrespected the singer in front of his boys ... an eyewitness tells TMZ.
According to someone who was on scene, Chris lost his cool in the parking lot of the famous Westlake Recording Studios in L.A. Sunday when Frank refused to shake his hand.
We're told Frank simply laughed at the gesture ... and Chris was so pissed he coldcocked Ocean and started an all-out war. As we first reported, Chris denies being the aggressor.
The fight quickly moved to the lobby of the studio ... and sources say the brawling posses demolished the place --"They managed to break almost everything in the room and scare all of the staff members working" says the witness.
We're told the receptionist called 911 ... and Chris booked it. As TMZ first reported, Frank stuck around for the cops ... and griped about how he felt "blindsided" by Chris.
One last thing -- we're told the parking situation at the recording studio is a serious hierarchy -- with the bigger artists taking the better spots ... and it's been that way for years. We're told Chris clearly felt he deserved the top spot ... and Frank disrespected him by taking it for himself.
Chris Brown & Frank Ocean
At Recording Studio
1/28/2013 7:57 AM PST BY TMZ STAFF
UPDATE: 5:20 AM PT: After the incident, Ocean tweeted "got jumped by chris and a couple guys. lol. i only wish everest [his dog] was there. cut my finger now I can't play w two hands at the grammys."
UPDATE 3:00 AM PT: Cops say they will continue to investigate and want to speak with Chris Brown. They refer to Ocean as "the victim" because he's the one who stuck around and spoke with police. Ocean said the fight started over a parking space (how L.A.) and Brown punched him. There were 6 people involved in the fight.
UPDATE 10:45 PM PT: Police have cleared the scene. We're told Chris Brown was not there when officers arrived -- but they did speak to Frank Ocean. At this point ... we're told no one wants to press charges, and no arrests have been made.
Chris Brown was involved in an all-out brawl with Frank Ocean Sunday night, and sources connected with Chris insist Ocean started it.
Chris was at Westlake Studio in the L.A. area listening to one of the artists he represents. The sources say as Chris went to leave, Frank Ocean and his crew blocked Chris from leaving. The sources say Frank said, "This is my studio, this is my parking spot."
We're told Chris went to shake Frank's hand ... and that's when one of Frank's people attacked Chris. Sources connected with Chris say one of Chris' friends jumped in front and hit Frank's friend.
Sources connected with Chris say Frank then came at Chris ... Chris pushed him away and they started brawling.
The police were called and are on scene now.
Below is a photo of Chris Brown in the studio. It appears the photo was taken before the fight ... but uploaded to CB's Instagram account AFTER the skirmish.