Djimon Hounsou's Baby Mama Arrested For Allegedly Assaulting Him

Djimon Hounsou told cops his baby mama hit him in the face after he told her to vacate his Atlanta townhouse ... and she's since been arrested for assault.

According to new legal docs, obtained by TMZ, Djimon went to police back in December and claimed his ex-girlfriend Riza Simpson, with whom he shares two children, struck his face with a closed fist after he tried to kick her out of a residence he owns.

The Atlanta Police Department says Djimon told cops their kids were upstairs in the house when their mother allegedly hit their father ... and police say Djimon told them the children didn't see the alleged assault, but may have heard it.

Fast forward to Friday ... APD executed an arrest warrant at the same home and took Simpson into custody for simple assault and obstruction for allegedly providing false information when confronted by officers ... both misdemeanors.

Cops say Simpson's kids were with her when she got busted ... and officers say they heard the children crying in the background when they banged on the front door.