The man who knocked out Eagles TE Dallas Goedert last year is breathing easier today ... he was just sentenced for the punch, but received nothing more than a slap on the wrist.

A South Dakota court official tells TMZ Sports ... Kyle Hadala -- the 30-year-old who rocked Goedert's face at a bar in June 2020 -- pled guilty to misdemeanor simple assault earlier this month and was sentenced that same day.

His punishment, though, was light -- considering he was facing up to 1 year in jail and a potential $2,000 fine.