R&B star Chris Brown celebrated Friday after a US judge released him from probation for assaulting then-girlfriend Rihanna in 2009.

The infamous attack left the female pop singer battered and bruised on the eve of the Grammys that year.

"IM OFF PROBATION!!!!!!! Thank the Lord!!!!!" Brown posted on his Twitter page shortly after the court hearing in Los Angeles, where Brown beamed as it was announced that he had fulfilled all his probation conditions.

LA Superior Court Judge James Brandlin said the 25-year-old had completed his roughly 1,000 hours of community labor, along with all other terms of his probation, including attending a domestic violence treatment program.

In June 2009, Brown pleaded guilty to assaulting Rihanna, who suffered facial injuries and was forced to cancel an appearance at that year's Grammy Awards.

Brown was sentenced to five years' probation, a yearlong domestic violence program and 180 days of community labor.

His probation was first revoked in 2013, after he was charged over a traffic accident in Los Angeles. Those charges were later dismissed, but he was ordered to perform an additional 1,000 hours of community labor.

It was revoked again last year, after he was accused of punching a 20-year-old man who was trying to get a photo with him in Washington. Brown's probation was later reinstated.