The former Barnsley man curled home a sublime free-kick from 20-yards after Jim Goodwin had been penalised for handball to ensure the managerless Terriers ended a miserable week on a low.
Vale took a shock lead against the run of play in the 27th minute when Louis Dodds intercepted Joe Scarr's back-pass to round Huddersfield goalkeeper Matt Glennon and slot home.
The Terriers equalised a minute before half-time when Michael Collins rifled home Gary Roberts' centre and went ahead six minutes after the restart when Ian Craney raced past John McCombe before he lashed a shot beyond Joe Anyon.
Robbie Williams then extended Huddersfield's advantage in the 65th minute, before Vale hit back through David Howland's brilliant chip.
Dodds made it three apiece five minutes from full-time when he latched on to Lee Collins' long ball and thumped a shot past Glennon before Richards secured the win.