Match ends, Birmingham City 2, Huddersfield Town 1.
Goals from Scott Hogan and Przemyslaw Placheta gave Birmingham their first win under new boss John Eustace and continued Huddersfield's poor start to the season.
Striker Hogan put the hosts ahead after five minutes with a superb diving header from Juninho Bacuna's cross.
And Polish winger Placheta scored just before the interval - his first goal since arriving on loan from Norwich last month.
Danny Ward pulled one back in the second half but the visitors were unable to find an equaliser.
Huddersfield, beaten by Nottingham Forest in last season's Championship play-off final, have now lost both their games under new boss Danny Schofield, who took charge after Carlos Corberan resigned in July.
It has been a tough summer for the Yorkshire club, who have also lost key players Harry Toffolo and Lewis O'Brien since their Wembley defeat - both to Forest.
They were disjointed in the opening 45 minutes and the second goal came as a result of some dismal Terriers defending.
After Tom Lees was caught out by a ball over the top, Hogan's cross was overhit but still found both Jordan James and Placheta unmarked at the far post.
James' effort was blocked and Placheta's follow-up was weakly palmed into the net by keeper Lee Nicholls, who should have done better.
Schofield's side were much better after the restart and reduced the deficit just after the hour mark when a slick move culminated in Sorba Thomas finding Ward, who fired home.
They then put Birmingham under pressure - and had appeals for a late penalty ignored when Jordan Rhodes went down in the box - but Eustace's team held on.
Birmingham City boss John Eustace told BBC Sport:
"The commitment of the players was there to be seen. Collectively, they have a point to prove and want to make the fans proud.
"My job is to get the fans and players connected again. And the fans have bought in.
"We wanted a team that are hard to play against. We've already got that - and the football will follow.
"I haven't taken any notice of what's going on off the pitch and neither have the players."
Huddersfield Town boss Danny Schofield told BBC Sport:
"First half we were off the pace, but we were much improved second half.
"Maybe we deserved something more in the end. The positive rhythm was with us.
"That was definitely encouragement that we can have another positive season. We just need to be more consistent.
"There's been a lot of change at the club and we can't afford to be negative."
- 5TrustyBooked at 58mins
- 17PlachetaSubstituted forFriendat 89'minutes
- 8DeeneySubstituted forGrahamat 75'minutes
- 9HoganSubstituted forJutkiewiczat 82'minutes
- 23Edmonds-GreenSubstituted forBoyleat 75'minutes
- 8AnjorinSubstituted forRhodesat 76'minutes
- 7ThomasBooked at 21mins
- 5RussellBooked at 32mins
- 22RudoniSubstituted forKoromaat 89'minutes
- 25WardSubstituted forHolmesat 76'minutes
- Gavin Ward
- Shots on Target
Second Half ends, Birmingham City 2, Huddersfield Town 1.
Foul by Duane Holmes (Huddersfield Town).
George Friend (Birmingham City) wins a free kick on the left wing.
Corner, Birmingham City. Conceded by Lee Nicholls.
Attempt saved. Auston Trusty (Birmingham City) left footed shot from the left side of the box is saved in the bottom left corner. Assisted by Juninho Bacuna.
Attempt saved. Juninho Bacuna (Birmingham City) right footed shot from the centre of the box is saved in the centre of the goal. Assisted by Jordan James.
Oliver Turton (Huddersfield Town) wins a free kick in the defensive half.
Foul by Auston Trusty (Birmingham City).
Substitution, Huddersfield Town. Josh Koroma replaces Jack Rudoni.
Substitution, Birmingham City. George Friend replaces Przemyslaw Placheta.
Foul by William Boyle (Huddersfield Town).
Lukas Jutkiewicz (Birmingham City) wins a free kick in the attacking half.
Foul by Jack Rudoni (Huddersfield Town).
Jordan Graham (Birmingham City) wins a free kick in the defensive half.
Substitution, Birmingham City. Lukas Jutkiewicz replaces Scott Hogan.
Foul by Jordan Rhodes (Huddersfield Town).
Dion Sanderson (Birmingham City) wins a free kick in the defensive half.
Attempt blocked. Jordan Rhodes (Huddersfield Town) right footed shot from the centre of the box is blocked. Assisted by Sorba Thomas.
Offside, Huddersfield Town. Duane Holmes tries a through ball, but Sorba Thomas is caught offside.