Loan signing Dave Kitson scored the only goal of the game for the Royals eight minutes from time at The Keepmoat Stadium on Tuesday night.
The result means Steve Coppell's side remain in third position in the Championship table but are now just four points behind second placed Blues and seven points behind leaders Wolves although still with one game in hand on both side's.Championship Table Top ThreeP Team Pld W D L F A Pts GD 1 Wolverhampton Wanderers 39 22 8 9 70 47 74 23 2 Birmingham City 39 20 11 8 46 32 71 14 3 Reading 38 19 10 9 65 35 67 30