Chris Brown is being accused of punching fellow R&B star Frank Ocean in a parking lot brawl Sunday night in West Hollywood.

An Los Angeles Sheriff's Department confirms "Chris Brown and the victim were involved in an altercation over a parking space. The altercation allegedly led to Chris Brown punching the victim." Brown's and Ocean's entourages then got involved and separated the singers.

Ocean took to Twitter to break news of the fight, writing, "got jumped by chris and a couple guys. lol. cut my finger now I can't play w two hands at the grammys." Ocean's debut album ORANGE is nominated for six Grammys.

This isn't Brown's first trouble with the law ... of course his 2009 pre-Grammys attack on then-girlfriend Rihanna is well documented. Then last year, Chris fought with Drake in a nightclub brawl.

In July, Brown denied making a homophobic slur against Ocean, who recently came out as bisexual, saying his first love was a man.