Justin Gimelstob -- an ex-tennis star and broadcaster -- says he did NOT beat the hell out of a man during a trick-or-treating run last Halloween ... telling TMZ Sports he's not a violent person.
As we previously reported ... Gimelstob -- a former doubles champ who's coached tennis star John Isner -- was arrested after he allegedly roughed up a man named Randall Kaplan on Oct. 31, 2018.
According to Kaplan ... Gimelstob punched him "more than 50 times" in the face and head during the alleged assault and threatened to "f**king kill" him.