8:23 AM PT -- TMZ Sports has obtained footage of the moment Mario Williams was confronted by the mother of his child inside of her Houston apartment ... and the standoff is intense.
We're told 34-year-old Williams had been banging on the front door of the apartment and the woman refused to let him in. So, he used a garage door opener that he allegedly made without her permission to gain entry.
Our footage shows the moment the woman confronts Williams at her garage entry door -- in which a very heated Williams accuses her of using their child's iPad to gain access to the contents of his iCloud .