Leicester's front two combined again in the 24th minute as Nugent fed a pass to Wood, whose low shot flew in off the post.
The game was over as a contest as the home side scored a third just before the break. Knockaert drawing out Smithies before passing to De Laet, who made no mistake.
There was to be no reprieve for Huddersfield after the restart, as Knockaert scored twice in three minutes.
The Frenchman first swept in from Paul Konchesky's cut back, before curling a shot beyond Ian Bennett, who had replaced the injured Smithies at half-time.
Arfield put Huddersfield on the scoresheet in the 59th minute, scoring at the second attempt after his first shot was saved by Kasper Schmeichel.
But Leicester's five-goal advantage was restored 15 minutes from time as substitute Waghorn volleyed home.
Leicester manager Nigel Pearson said:
"The players have shown a lot of character. Chris Wood played a very positive part in what a was a very good team performance. His attributes fit the bill for a what we are looking for.
"He is a team player and works very hard and shows a lot of football intelligence as well. It is pleasing that that he has got off to such a good start but it is about the group.
"All our forwards have a lot of flair and potential and we now have a lot of options moving forward.
"It was a thoroughly professional performance today."
Huddersfield manager Simon Grayson said: "
We wanted to start the new year in a positive manner but today could not have been any worse for us.
"We wanted to be hard to beat and make sure it was a difficult afternoon for Leicester and make sure they didn't have an easy ride.
"But the way we started the game allowed them to dictate to us what they wanted to do. And before we knew it we were a couple of goals down and too many times made the wrong decisions."
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