It took a Luton penalty against the post and an 89th minute goal from naby Sarr to secure a vital three points against a play-off rival in the televised game, and the Terriers play two more over Easter, in Queens Park Rangers and Middlesbrough.
"It was built up as a really important game and that was evident by the table," centre-back Lees said of the Luton victory. "With the position of the two teams we knew it was going to be a good quality game and it was one we were absolutely delighted to win and it was a really good performance as well."
Asked if he felt the game was tentative, he replied: "I think it's because it's two teams of similar quality, two teams that are high energy as well and like to press each other but I actually thought we started the game really well and positively, and on the front foot.
"Then in a game like where you're so similarly matches, it's going to be tight, there's not going to be many clear-cut chances.
"Playing these teams at this moment of the season, if we're going to get in the play-off that's how it's going to be. It's going to be fine matches.
"That was what happened the other night. There weren't a lot of chances but we scored two goals with the opportunities we've got."
Huddersfield have no fresh injury problems going into the Easter weekend, where they play late on Good Friday and early on Easter Monday for the benefit of television.
Visitors QPR's play-off chances have faded in an injury-hit poor run of recent form, six points behind Sheffield United with five matches to play, but they showed earlier in the season what a good team they are.
Middlesbrough are eighth, but winning their game in hand would put them level on points with the sixth-placed Blades, and they have home advantage on Monday.