Terrance Allen, an 11-year-old Brooklyn boy, stabbed his mother’s live-in boyfriend, Timothy (Mohammad) Pender, to stop him from chocking his mother.

Pender, an ex-con, also assaulted the boy’s cousin, 27-year-old Kenyatta Parker, during the Saturday night attack. At 11:20 p.m. Pender allegedly beat Allen’s mother, Tracy Anderson, for a half an hour. He started beating Parker when she tried to stop the attack.

Little Terrance felt he had to do something. Fast.

“I had a feeling something was going to happen,” the soft-spoken boy said an exclusive interview as his mom, shaken and fighting back tears, looked on. “I was frightened.”