TMZ Sports has obtained the 911 call made by a witness who saw ex-NFL lineman Barret Robbins on a violent rampage in Florida last week ... and it sounds terrifying.
The caller initially reports a "huge drunk man just literally walked into (a pub) punched this kid in the face" in the late hours of August 8th.
We broke the story ... the former Oakland Raiders lineman (who was listed at 6'3", 320 during his playing days) was leaving a bar in Boca Raton when the rampage began.
The caller says Robbins was yelling to himself and waving his hands around -- before attacking two innocent women outside of a nearby hotel.