NFL running-back Ray Rice has won his appeal against an indefinite suspension from the game, and is now eligible to play again immediately.
Rice, 27, was handed an indefinite ban in September when a video emerged of him punching his fiancee in the face.
The player was released by the Baltimore Ravens, but he is now allowed to play should he sign for a new team.
The appeal, heard on 5 November but announced on Friday, had to decide if the NFL overstepped its authority.
American football's governing body had modified Rice's two-game suspension, making it indefinite after the video of the incident went public.
Rice has been eligible to sign for a new team since his ban was put in place, but he had not yet accepted a contract.
Rice and his wife Janay - who married after the incident - testified at the hearing, as did NFL security chief Jeffrey Miller and Ravens general manager Ozzie Newsome.
In her decision, US district judge Barbara S Jones wrote: "Because Rice did not mislead the commissioner and because there were no new facts on which the commissioner could base his increased suspension, I find that the imposition of the indefinite suspension was arbitrary.
"I therefore vacate the second penalty imposed on Rice.
"The provisions of the first discipline - those regarding making continued use of counselling and other professional services, having no further involvement with law enforcement, and not committing any additional violations of league policies -still stand."
The NFL is yet to comment.
Earlier in November the owner of the Jacksonville Jaguars Shahid Khan told the BBC the NFL "has to play a leadership role" when it comes to the issue of domestic abuse.