Chris Brown -- Pleads GUILTY In D.C. Assault Case

Chris Brown just accepted a plea deal in his Washington D.C. assault case ... pleading guilty, and telling the judge he just wants this case to go away so he can go on tour.

Brown had been charged with misdemeanor assault for punching a man in the face outside his tour bus last October. The judge sentenced him to time already served.

Brown apologized in court ... saying the case had derailed his career for the past year.

His bodyguard, Christopher Hollosy was also convicted of misdemeanor assault in April in connection with the incident ... but has not yet been sentenced.

Funny, Brown only served 2 days in a D.C. jail -- but ended up doing 108 days in L.A. County lockup because the D.C. case violated his probation in the Rihanna case.