Law enforcement sources tell TMZ ... Grace Jabbari was arrested Wednesday evening at Manhattan's 10th Precinct for allegedly attacking the "Creed III" actor after Majors filed a cross complaint against her back on June 22.

Our sources say Jabbari allegedly scratched Majors on his right hand and smacked him across the face with an open hand, causing a cut to his cheek and ear pain. She then allegedly tore buttons off his coat, and damaged the front pocket.

We're told she's being booked for misdemeanor assault and criminal mischief.

There's one big problem ... the Manhattan D.A.’s office filed court papers Tuesday, saying it informed the NYPD last month it has no intention of prosecuting Jabbari for "the belated allegations made by defendant [Majors] regarding the incident on March 25, 2023."

Clearly, the D.A. and police are not seeing eye to eye on this case -- NYPD believes it has probable cause to arrest Jabbari, and even though the D.A. didn't ... cops are still booking her.

As for Majors, he was charged with misdemeanor assault and harassment in March after Jabbari accused him of assaulting her inside a Manhattan apartment. Jabbari was later treated for head and neck injuries at a local hospital and released.

Majors believes his side has a smoking gun proving his innocence -- security footage of Jabbari partying all night after the alleged attack. In court docs, Major's attorney Priya Chaudhry noted Jabbari was seen walking normally into the establishment, ordering drinks, dancing and pushing her hair back with the hand she claimed Majors injured.