Lee Clark's woes continued as former club Huddersfield inflicted more misery on the under-fire Birmingham boss.
Striker Jermaine Beckford netted the first-half winner when he swept in James Vaughan's cross to lift Town back into the Championship top six.
Clark, who was forced to dismiss reports of a player revolt this week, saw substitute Nikola Zigic dismissed as the Blues dropped to fourth bottom.
Blues' Nathan Redmond crashed a curling first-half effort against the post.
City were booed off the pitch as the home fans watched back-to-back league defeats at St Andrew's for the first time since March 2011. Huddersfield's win came after last month's heavy 5-0 defeat by Barnsley - the club's biggest home league defeat in 25 years.
Terriers end 16-year wait
Beckford's goal helped Huddersfield secure their first win against Birmingham since 1996.
But any hopes held by Clark, who applauded both sets of supporters before kick-off, of a positive reaction against the Terriers were dashed by Beckford's first goal for the West Yorkshire club since joining on loan from Leicester.
Adam Clayton found Vaughan in acres of space down the right and he crossed for Beckford, who eased ahead of Steven Caldwell to convert from close range.
Blues were in need of inspiration and Redmond tried to do just that with a sweet curling effort against the inside of the far post from 20 yards.
But their hopes of securing at least a point were hampered when they were reduced to 10 men with 16 minutes remaining as Zigic was shown a straight red card for a high challenge on Callum Woods.
Birmingham manager Lee Clark:
"Football fans are working-class people, they want to see someone having a right good go for their team, in terms of tackling, heading, competing.
"There were four of five players in the first half who never did that. They've got to stand up and be counted. Okay, I'm responsible but I can't keep saying that. Can they start taking responsibility?
"I'm getting the flak from supporters, no problem I can take that. But I'm not sitting in the dressing room telling them not to tackle, to pussyfoot around, telling them to mis-place passes.
"They can't just hide behind me all the time, they've got to come out fighting."
Huddersfield boss Simon Grayson:
"I think deservedly we got the win, getting any points in the Championship is never easy.
"We started the game very well, very brightly, pressurised Birmingham when we needed to, played in the right areas with purpose and created some good opportunities. I'm delighted from that point of view.
"The back end of the game when Birmingham had nothing to lose we were resilient and withstood some pressure. To come here and get a result is satisfying from my point of view after two tough previous defeats."
- 01 Butland
- 04 Caldwell
- 06 Davies (Hancox - 80' )
- 23 Spector
- 30 Robinson Booked
- 31 Hurst (Mullins - 63' )
- 07 Burke
- 15 Elliott
- 18 Fahey (Zigic - 46' Dismissed )
- 22 Redmond
- 29 Lita
- 13 Doyle
- 27 Hancox
- 08 Mullins
- 10 Ambrose
- 09 King
- 11 Lovenkrands
- 19 Zigic
- 01 Smithies
- 02 Woods (Dixon - 90' )
- 05 P Clarke
- 06 Gerrard
- 32 Hunt Booked
- 04 Norwood
- 08 Clayton
- 11 Ward (Novak - 85' )
- 24 Southern
- 18 Vaughan (Hammill - 67' )
- 21 Beckford
- 13 Bennett
- 03 Dixon
- 15 Wallace
- 14 Hammill
- 22 Robinson
- 07 Scannell
- 09 Novak
Live Text Commentary
Full Time The final whistle goes and the game is over.90:00 +5:57
Free kick taken by Oliver Norwood.90:00 +5:57 Booking
Booking Paul Robinson goes into the referee's book for unsporting behaviour.90:00 +5:48
Jack Hunt fouled by Paul Robinson, the ref awards a free kick.90:00 +4:35
Corner taken right-footed by Wade Elliott.90:00 +4:35 Substitution
Substitution Paul Dixon joins the action as a substitute, replacing Calum Woods.90:00 +4:04
Wade Elliott takes a shot. Save made by Alex Smithies.90:00 +1:18
Free kick taken by Wade Elliott.90:00 +1:18 Booking
Booking Jack Hunt is cautioned by the ref for unsporting behaviour.90:00 +1:05
Foul by Jack Hunt on Wade Elliott, free kick awarded.88:26
Jermaine Beckford takes a shot. Save by Jack Butland. Adam Hammill decides to take the corner short.87:17
Keith Southern gives away a free kick for an unfair challenge on Nathan Redmond. Free kick taken by Nathan Redmond.86:58
Adam Hammill takes a shot. Save made by Jack Butland.85:29
Mitch Hancox takes a shot. Blocked by Jack Hunt. Corner taken by Wade Elliott.84:08
Alex Smithies restarts play with the free kick.84:08 Substitution
Substitution Lee Novak is brought on as a substitute for Daniel Ward.84:08
Paul Robinson handles the ball and concedes a free kick.83:19
Corner taken right-footed by Wade Elliott, Anthony Gerrard manages to make a clearance.77:45
Wade Elliott takes the direct free kick.77:45 Substitution
Substitution Mitch Hancox comes on in place of Curtis Davies.
Foul by Oliver Norwood on Wade Elliott, free kick awarded.75:20
Effort on goal by Adam Hammill from outside the penalty box goes harmlessly over the bar.73:40
Oliver Norwood crosses the ball in from the free kick, Steven Caldwell manages to make a clearance.73:40 Dismissal
Dismissal Nikola Zigic sent off.73:08
Nikola Zigic gives away a free kick for an unfair challenge on Calum Woods.72:15
Jonathan Spector fouled by Adam Clayton, the ref awards a free kick. Direct free kick taken by Jack Butland.71:13
Peter Clarke fouled by Nikola Zigic, the ref awards a free kick. Alex Smithies takes the direct free kick.70:33
Peter Clarke gives away a free kick for an unfair challenge on Jonathan Spector. Jack Butland restarts play with the free kick.70:06
Oliver Norwood decides to take a short corner.69:29
Corner taken right-footed by Oliver Norwood from the left by-line to the near post, clearance by Nikola Zigic.66:47 Substitution
Substitution Adam Hammill joins the action as a substitute, replacing James Vaughan.66:47
Nathan Redmond has a shot on goal from outside the area which misses right.62:52 Substitution
Substitution James Hurst leaves the field to be replaced by Hayden Mullins.59:57
Shot from long range by Keith Southern goes wide of the left-hand post.57:40
Keith Southern takes a shot. Blocked by Wade Elliott. Inswinging corner taken right-footed by Oliver Norwood from the left by-line, Keith Southern has an effort at goal from just outside the box which goes wide of the right-hand upright.56:36
Wade Elliott gives away a free kick for an unfair challenge on Adam Clayton. Free kick taken by Oliver Norwood.54:43
Christopher Burke takes a shot. Alex Smithies makes a save. Corner taken right-footed by Wade Elliott to the near post, Adam Clayton makes a clearance. Christopher Burke has an effort from just inside the box that misses to the left of the goal.54:19
Oliver Norwood challenges Nathan Redmond unfairly and gives away a free kick. Paul Robinson restarts play with the free kick.50:41
Keith Southern takes a shot. Blocked by Jonathan Spector.48:18
Corner taken right-footed by Nathan Redmond to the near post, clearance made by Anthony Gerrard. Inswinging corner taken from the left by-line by Nathan Redmond, save by Alex Smithies.47:45
Nathan Redmond takes a shot. Anthony Gerrard gets a block in.47:20
Wade Elliott takes a shot. Jack Hunt gets a block in.46:34
Unfair challenge on Peter Clarke by Nikola Zigic results in a free kick. Direct free kick taken by Peter Clarke.45:01
The game restarts for the second half.45:01 Substitution
Substitution Nikola Zigic comes on in place of Keith Fahey.45:00 +1:11 Half time
Half Time The first half comes to an end.40:44
Daniel Ward takes a shot and went wide left of the target.40:20
Foul by Keith Fahey on Oliver Norwood, free kick awarded. Adam Clayton restarts play with the free kick.39:39
Daniel Ward takes a shot.36:32
Long range shot by Keith Fahey goes wide right of the goal.34:36
Daniel Ward takes a shot. Save by Jack Butland. Daniel Ward takes a shot. Save made by Jack Butland. Peter Clarke challenges Leroy Lita unfairly and gives away a free kick. Free kick taken by Nathan Redmond.33:01
Outswinging corner taken by Wade Elliott, Anthony Gerrard makes a clearance. Wade Elliott takes the outswinging corner, Peter Clarke makes a clearance.32:08
Foul by James Vaughan on Jack Butland, free kick awarded. Free kick taken by Jack Butland.31:33
Corner taken right-footed by Oliver Norwood, Paul Robinson manages to make a clearance.29:57
James Vaughan concedes a free kick for a foul on Paul Robinson. Paul Robinson takes the direct free kick.29:34
Nathan Redmond produces a right-footed shot from just outside the penalty area that bounces off the post.25:31
James Hurst fouled by Keith Southern, the ref awards a free kick. Free kick taken by Keith Fahey.24:11
Assist by James Vaughan.24:11 Goal scored
Goal! - Jermaine Beckford - Birmingham 0 - 1 Huddersfld Jermaine Beckford finds the back of the net with a goal from inside the box to the bottom right corner of the goal. Birmingham 0-1 Huddersfield.23:24
Daniel Ward is flagged offside by the assistant referee. Free kick taken by Jack Butland.20:42
Jermaine Beckford is ruled offside. Direct free kick taken by Jack Butland.19:14
Christopher Burke produces a cross.18:21
Free kick awarded for a foul by Daniel Ward on James Hurst. Direct free kick taken by Jack Butland.16:52
Inswinging corner taken from the left by-line by Oliver Norwood.15:47
Jonathan Spector challenges Jack Hunt unfairly and gives away a free kick. Free kick taken by Peter Clarke.11:35
Christopher Burke gives away a free kick for an unfair challenge on Calum Woods. Calum Woods takes the free kick.10:27
Nathan Redmond takes a shot. Clearance by Anthony Gerrard. James Hurst takes a shot. Blocked by Keith Southern. Wade Elliott takes a inswinging corner from the left by-line played to the near post, Adam Clayton manages to make a clearance.7:28
Corner taken right-footed by Oliver Norwood, Effort on goal by Peter Clarke from inside the penalty area goes harmlessly over the bar.6:53
Wade Elliott challenges Jack Hunt unfairly and gives away a free kick. Direct free kick taken by Peter Clarke.6:17
Adam Clayton takes a shot. Blocked by Curtis Davies.3:46
Steven Caldwell concedes a free kick for a foul on Jermaine Beckford. Free kick crossed right-footed by Oliver Norwood from right wing, Steven Caldwell makes a clearance.2:07
Daniel Ward takes a shot. Blocked by James Hurst. Oliver Norwood takes the inswinging corner, clearance by Curtis Davies.0:27
Effort from inside the area by James Vaughan misses to the right of the target.0:00
The referee gets the game underway.
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