Town suffered a first home Championship defeat of the season as Huddersfield stayed in pole position in the table.
Tom Lawrence and Grant Ward had both gone close for Blues, while Elias Kachunga had hit the inside of the post before the Terriers got the vital breakthrough just before the hour. Town switched off from a corner and Chris Schindler lost his marker before burying his header in the net.
Town stayed with the same side that drew with Brighton in midweek, Luke Varney taking a place on the bench after recovering from injury.
Bart Bialkowski, who picked up the Player of the Month award as voted for by the fans before kick-off, was in the right place to keep out Jonathan Hogg’s close range header from a corner as the Championship leaders had a clear chance to open the scoring inside five minutes.
Leon Best responded for Blues with a lovely turn away from his marker but he couldn’t find Kevin Bru with his pass, Josh Emmanuel then winning a free-kick on the edge of the Terriers’ box that Lawrence sent just wide.
Blues had an anxious moment at the other end when Christophe Berra’s header cannoned back off Cole Skuse but avoided Aaron Mooy and was safely gathered by Bialkowski.
Huddersfield were inches away from scoring midway through the half when Kachunga hit the inside of the post from the edge of the box and from the rebound, Bialkowski had to beat out Nahki Wells’ left footer.
Jonas Knudsen fired high over the bar from a free-kick as Town searched for the opener, Luke Chambers seeing a header blocked by Mark Hudson from a corner before Ward got on the end of Best’s header but his lob went the wrong side of the post.
Lovely footwork by Bru and then a clever pass saw Best threaten on the edge of the box but Huddersfield smothered the danger before the half-time whistle.
Huddersfield made a change at the break, with Rajiv van La Parra on for Dean Whitehead as the Terriers chased a first win at Portman Road since 1996.
Bru couldn’t make it pay on the edge of the box after Best had robbed Schindler, the Mauritius international then weaving his way to goal but Hogg cleared the danger.
Town made a double change on 56 minutes with Freddie Sears on for Bru and Teddy Bishop replacing Ward.
A minute later Huddersfield were ahead, Mooy sent in a corner, Town switched off and Schindler found the net with a flashing header.
Berra denied Sean Scannell from close range after La Parra got around the back of the Town defence, then Sears produced a save from Danny Ward with a right foot strike from the edge of the box.
Michael Hefele replaced the injured Schindler, who left the field with a cut, Ward quickly off his line to prevent Sears getting in.
Berra timed his tackle to perfection to clear from the breaking Kachunga, Ward then pleased to get a second bite of the cherry and hang on to the ball after failing to clear from Knudsen’s cross.
Varney replaced Lawrence for the closing stages, the striker firing wide as Town pressed for the equaliser but it was an equaliser that wouldn’t come as Blues’ goal problems continued.
Town: Bialkowski, Emmanuel, Chambers, Berra, Knudsen, Skuse, Douglas, Ward (Bishop 56), Lawrence (Varney 86), Bru (Sears 56), Best. Subs not used: Gerken, Kenlock, Digby, Grant. Booked: Douglas.
Huddersfield: Ward, Smith, Whitehead (van La Parra 46), Hudson, Hogg, Scannell (Cranie 87), Kachunga, Mooy, Lowe, Wells, Schindler (Hefele 70). Subs not used: Coleman, Holmes-Dennis, Payne, Palmer. Booked: Hogg.
Att: 16, 146