The Terriers moved up to third in the League One table with the win and their impressive unbeaten run now stretches to 33 regular season league games.
"That's our top performance of the season," Clark said.
"We looked a threat all night to score goals. We had a work ethic from the front two that the rest of the team followed."
Lee Novak's double and a header from Oscar Gobern put Huddersfield 3-0 up before the break and Clark was delighted with the way his men maintained the advantage.
"I knew Sheffield United would come out second half and put us under bits of pressure but we got blocks in and if we didn't get the blocks in the goalkeeper made some decent saves.
"All in all I'm delighted with the performance."
Clark is very happy with the form of his strikers as Novak, Alan Lee and substitute Jordan Rhodes continue to provide plenty of problems for League One defences.
"They're on fire at the moment. I just wish Alan could have got one of the goals because he thoroughly deserved one that's for sure.
"It's nice when you've got a goalscorer like Jordan Rhodes to bring off the bench.
"All three of them are scoring on a regular basis which is fantastic for us."