Birmingham maintained their three-point lead at the top of the Coca-Cola Championship following a 3-0 win at Sheffield Wednesday.
Stephen Clemence, Gary McSheffrey and Cameron Jerome were the Blues' scorers but the hosts had their share of chances at Hillsborough with goalkeeper Maik Taylor in inspired form.
Chris Brunt hit a 35-yard strike which Taylor held at the second attempt and the keeper then made a one-handed save from Marcus Tudgay's close-range shot.
However, Blues took the lead against the run of play when Mark Crossley could not hold Jerome's long-range shot and Clemence pounced just three minutes before the break.
Wednesday did all the attacking in the second half before McSheffrey got his 12th of the season and Jerome sealed his side's sixth away win of the season.
Derby stayed in second with a 1-0 win against Crystal Palace courtesy of David Jones.
Jones struck after 22 minutes to claim his eighth goal of the season after good work by Arturo Lupoli.
Lupoli then hit a shot just wide after weaving his way into a shooting position but the Rams could not manage any further goals.
West Brom claimed a 5-0 victory over an outclassed Coventry side at The Hawthorns.
Diomansy Kamara struck twice and opened the scoring in the first minute.
Albion went further ahead through Kamara's penalty before Jason Koumas scored the third following a break from a Sky Blues' corner.
Kevin Phillips put the Baggies further ahead before full-back Paul Robinson's diving header made it five.
Colchester climbed into the play-off positions with a 3-0 victory over Stoke.
Jamie Cureton scored twice - the first a curling shot in the third minute for his 11th of the season before he volleyed home after 17 minutes.
Ricardo Fuller had two good chances for the Potters but it was 3-0 through Richard Garcia.
Preston claimed a 3-0 win over Plymouth at Deepdale.
Danny Pugh put the Lilywhites ahead after 12 minutes when he rifled in a 25-yard volley from David Nugent's assist.
Brett Ormerod made it two four minutes before the break and Graham Alexander rounded off the scoring with a penalty after 56 minutes.
Southampton moved into fourth in the table after coming from behind to beat Norwich at St Mary's.
Rob Earnshaw's 14th goal of the season gave Norwich a 22nd-minute lead against the run of play.
However, Gareth Bale levelled with a free-kick from outside the box which gave the keeper no chance after 41 minutes before Kenwyne Jones struck the winner.
Promotion hopefuls Cardiff continued their miserable form with a 4-1 drubbing at lowly Hull.
Second-bottom Hull took just six minutes to take the lead through Damien Delaney before the second goal came three minutes later through Dean Marney.
Craig Fagan put the Tigers further ahead after converting a one-on-one with the goalkeeper.
Michael Chopra pulled one back with his 12th of the season (55) before Michael Bridges (71) restored the three-goal cushion and the Tigers could even afford to miss a penalty.
Leeds dropped to second from bottom following a 1-0 defeat at Ipswich.
Gavin Williams volleyed Town into the lead on the stroke of half-time against Leeds at Portman Road.
Leeds' misery was complete when Kevin Nicholls was sent off five minutes from time for two bookable offences.
Wolves claimed a 1-0 win at QPR thanks Michael Kightly's 49th-minute goal while Leicester beat Barnsley 2-0 thanks to Elvis Hammond and Levi Porter.
Burnley squandered a two-goal lead against Sunderland at Turf Moor.
The Clarets went ahead when they counter-attacked from their own penalty area and Kyle Lafferty whipped the ball into the net.
Dwight Yorke made a dreadful mistake when he headed back to his own keeper and Lafferty pounced for his second.
Grant Leadbitter pulled one back with 10 minutes to go before David Connolly hit a last minute equaliser from 25 yards.