Cameron Jerome repaid manager Steve Bruce's faith in him by scoring both goals - one after just 30 seconds - as Birmingham recorded its first Premier League victory of the season in a 2-1 margin at Derby.
Jerome, making his first start of the campaign, had an instant impact as he combined with Mikael Forssell to open the scoring almost straight from the kick-off.
Matt Oakley equalised for Derby in the 51st minute, but Jerome had the last word, firing home from substitute Sebastian Larsson's flick-on just after the hour.
It left the Pride Park hosts, promoted via the play-offs, bottom of the table after its joint-worst start to the Premier League, having also only taken one point from four matches in 1999-2000.
With only half a minute gone, some neat interplay on the edge of the penalty area saw former Cardiff striker Jerome play a quick one-two with Forssell and burst into the left-hand side of the box before rolling a shot across Stephen Bywater and into the far corner of the net.
Derby's first effort came in the seventh minute when Gary Teale played in Craig Fagan, but Radhi Jaidi came across to half-block his shot and the ball rolled harmlessly to the recalled Maik Taylor.
Taylor was forced into his first save when Teale unleashed a shot from 25 yards and although the Birmingham keeper tipped the ball around his right-hand post, referee Lee Probert gave a goal-kick.
Three minutes before half-time Bywater raced off his line to deny Fabrice Muamba after the midfielder broke through, while at the other end Teale saw his hooked right-foot shot bounce agonisingly wide of Taylor's left-hand post.
The first real threat of the second half came from Birmingham, which broke swiftly from a Derby corner just 90 seconds after the restart.
Jerome picked up the ball midway inside his own half and carried it 40 yards, but his pass to Forssell pushed the Finland striker wide and he scuffed a shot off target.
Jerome wasted the chance for a second when he sprang the offside trap and pushed the ball past Bywater but opted to pull it back to Forssell rather than shoot from a wide angle and his partner's effort was deflected for a corner.
He was made to pay for that error as Derby went straight down the other end and scored in the 51st minute.
Lewis found space down the left and when he crossed to the far post, Oakley was there to volley home the equaliser.
Davis, who looked to have been carrying an injury after a first-half clash with Forssell, was replaced by Darren Moore on the hour, with Forssell also making way for Larsson.
Larsson's impact was immediate as with his first touch he flicked on a cross from Stephen Kelly and Jerome, at the far post, fired home Birmingham's second.
Having gone ahead again, Birmingham was content to eat up time in possession, but Derby stepped up the pressure and there was some frantic defending by the visitors.
However, Derby lacked a cutting edge up front and Bruce's side held on despite four minutes of added time for an important victory.
English Premiership League
Derby 1 (Oakley 51)
Birmingham City 2 (Jerome 1, 63)