Robins relegated after Blues loss
Bristol City's relegation to League One was confirmed after a 1-0 defeat at home to Birmingham ended their six-season stay in the npower Championship.
Wolves' 1-0 win against Hull coupled with Barnsley's 1-1 draw against Derby left the Robins 11 points adrift of safety with nine to play for.
Sean O'Driscoll's appointment in mid-January saw a significant upturn in results at Ashton Gate but poor away form and back-to-back home defeats in quick succession proved their downfall.
Wade Elliott scored the only goal, slipping the ball past Tom Heaton in the 16th minute to move Blues up to 12th in the table.
The home side were without injured trio Liam Fontaine, Stephen Pearson and Marvin Elliott while Birmingham boss Lee Clark named an unchanged line-up.
After a quiet start, the Robins had the first chance when Brendan Moloney's cross was cleared to Liam Kelly but his long-range volley flew wide of Jack Butland's goal.
Blues responded when a pinpoint cross from Shane Ferguson found Nikola Zigic who sent a header back across goal but Heaton saved superbly.
Birmingham took the lead shortly afterwards when a clever run and pass from Nathan Redmond sent Elliott clear and he coolly slotted home his ninth goal of the season.
The visitors were on top, with Ferguson not too far away with a 30-yard free-kick that just cleared the crossbar and Zigic putting the ball in the net only to see a flag for offside.
Bristol City, who went into the game on the back of a five-match winless streak, were inches away from an equaliser in the 39th minute when Steven Davies drilled the ball across the face of goal and the onrushing Sam Baldock just failed to make contact at the far post.
A superb jinking run and low drive from Redmond almost doubled Birmingham's advantage before the break but the ball whistled past the right-hand post.
The Championship's bottom club started the second half brightly and should really have levelled when Davies slipped the ball through for Baldock.
He decided to take his shot early and Butland saved smartly.
Blues had Paul Robinson to thank moments later when Baldock again burst through the middle but the veteran defender did just enough to knock the ball away.
Baldock spurned yet another good opening after 69 minutes when he connected well with Davies' knock-down but his 20-yard effort went wide.
Birmingham could have sealed it late on through Zigic, who should have done better when picked out by Ravel Morrison, and then Burke who wriggled free of his marker and beat Heaton with a low shot but Greg Cunningham cleared off the line.