Both sides scrapped it out early on but it was the Terriers who looked likelier to open the scoring, having several near misses.
Pawel Abbott's winding run past Craig James and George Pilkington almost resulted in a goal but his shot flew wide after six minutes. Port Vale did have their chances but they were few and far between.
Billy Paynter's shot from James O'Connor cross in the 44th minute had to be cleared off the line by Andy Holdsworth but that was the home side's only real threat.
The pacy midfield combination of Danny Schofield and Chris Brandon caused the Vale defence problems all afternoon but it took until the 62nd minute for Town to take the lead.
After careful build-up play and with little room to work in, Brandon laid the ball off for Abbott who slotted his shot past Mark Goodlad from 15 yards.
Huddersfield doubled their lead five minutes later when Pilkington's slip allowed Polish Under-21 international Abbott to run unchallenged towards goal and roll the ball under the oncoming keeper.
The away side finished the rout in the 75th minute when Brandon picked out Abbott again from the left and he had space and time to calmly smash home past the helpless Goodlad.