Ex-MLB Star Kris Benson to Judge -- Keep My Crazy Wife Away from Our Kids

2:48 PM PT -- A judge just awarded Kris full custody and revoked Anna's visitation rights.

Former MLB pitcher Kris Benson isn't taking any chances after his estranged wife Anna Benson was arrested for allegedly threatening to kill him with a handgun -- TMZ has learned, he ran to court asking to have her stripped of custody of their children.

Kris filed the emergency motion Tuesday in Georgia, demanding full legal and physical custody of his and Anna's three kids.

Kris had previously been awarded primary physical custody, but still shared legal custody with Anna ... and now he's clearly scared to give her any custody at all.

Kris says Anna's arrest for felony assault this week shows she's too unstable to have custody. He claims she has also displayed bizarre behavior recently -- including paranoia that the FBI is following her, as well as possible hard drug use.

As we reported, Anna was arrested early Monday morning after allegedly raiding Kris' home with a handgun, a metal baton, and a bulletproof vest ... demanding $30,000 in cash. According to Kris' new legal docs, she also brought a hatchet and a stun gun, and threatened to kill him.