Burton have announced the 40-year-old has been appointed as the replacement for the sacked Lee Clark
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Midfielder David Cotterill lit up an otherwise dour SkyBet Championship encounter with a stunning free-kick to earn Birmingham a 1-0 win against Huddersfield.
The swerve on Cotterill's 70th-minute effort appeared to deceive Huddersfield keeper Alex Smithies.
Blues striker Clayton Donaldson was fouled on the right edge of the box by Anthony Gerrard and Cotterill stepped up for the set-piece.
Birmingham beat Nottingham Forest 2-1 in a frantic finish at St Andrew's to increase their unbeaten run to five games under Gary Rowett.
Birmingham appeared to be coasting to a comfortable win following David Cotterill's first-half strike when Britt Assombalonga grabbed a fine equaliser in the 84th minute.
Assombalonga was Forest's hero with his goal but he then became their villain five minutes later when he handled the ball in the area and was sent off for the offence.
Paul Caddis, who had missed the previous penalty he had taken at St Andrew's, made no mistake from the spot sending goalkeeper Karl Darlow the wrong way.
Birmingham have parted company with manager Lee Clark following a poor start to the Sky Bet Championship season.
Blues are one place outside the relegation zone having won just two of their 12 league games so far, and only retained their second-tier status in the final seconds of the last campaign.
A statement on the club's official website read: "Birmingham City Football Club has parted company with Lee Clark and Steve Watson with immediate effect.
"The search for a successor has already begun and the board will look to make an appointment in the very near future."
Wigan wiped the floor with beleaguered Birmingham in a horribly one-sided Sky Bet Championship encounter at the DW Stadium.
Callum McManaman was again the pick of the Latics players with two first-half goals as the home side led 3-0 at the break.
Andrew Taylor and substitute Martyn Waghorn grabbed the others for Wigan, who could have won even more comprehensively than 4-0 such was their total superiority.
Birmingham have confirmed that they are in 'advanced discussions' with a British consortium over the sale of the club.
Birmingham International Holdings Limited, the holding company of the football club, made an announcement to the Hong Kong Stock Exchange (HKSE) over the course of the weekend.