The man accused of sucker punching Dallas Goedert in the face at a bar last month is officially fighting back in his assault case -- pleading NOT GUILTY to the charges Friday, a court official tells TMZ Sports.
30-year-old Kyle Hadala allegedly clocked the Philadelphia Eagles tight end during a bar brawl on June 19 in South Dakota ... and the video of the incident did NOT look good for Hadala.
In the clip ... you can see Hadala uncorks a right hand to Goedert's temple, knocking him to the ground.