Winger Gary Roberts opened the scoring on the stroke of half-time and the former Ipswich player laid on Nathan Clarke's and Michael Collins' second-half strikes before top-scorer Jordan Rhodes added the coup de grace in stoppage time.
It was the Terriers' sixth win in eight home outings and Clark said: "I was delighted with our attacking play and some of the finishing was outstanding.
"We are spoiled for choice in terms of matchwinners who can damage in the final third of the field. I thought our three wide men, Roberts, Ainsworth and Anthony Pilkington all had terrific games.
"My only disappointment is they had a few too many chances late on.
"Our home form is superb and we now need to convert that into good away results. Our game at Oldham next week is crucial and we have to get a good result there to stay in touch at the top."