Terrence Howard's Ex-Wife -- He Sucker Punched Me In the Face

Terrence Howard's ex-wife filed legal docs with a graphic allegation -- that the actor sucker punched her in the face, grabbed her by the neck and threw her against the wall.

In the docs -- obtained by TMZ -- Michelle Ghent alleges the brutality occurred during a trip last week to Costa Rica. She says the fight started after she told Terrence she had no interest in firing up a relationship with him -- they divorced in May.

Michelle says after Terrence hit her, he glared at her and walked over to a bedside table where he kept 2 curved knives -- 4-6 inches in length.

Michelle says she panicked and then pepper sprayed him. At that point she claims Terrence knocked her down and then kicked her repeatedly in the head.

In addition to the black eye, Michelle says she suffered contusions and swelling.

And, she says, he referred to a prior warning he had given her on a trip to Bora Bora -- threatening to kill her.

For his part, Terrence claims in his legal docs that she made up the story to damage him, timing it for his movie premiere of "The Butler." Terrence claims she threatened to kill him and he believes she's serious. He also says she's been admitted to a psych hospital in the past.