Leeds boss Brian McDermott endured an unhappy return to Reading, as Adam Le Fondre scored a 96th-minute winner for the Royals in the Championship.
The striker McDermott brought to the Madejski Stadium from Rotherham in 2011 converted from Royston Drenthe's free-kick to send his side seventh.
The chance came after Stephen Warnock received his second yellow card of the match for a trip on Le Fondre.
Luke Varney wasted the best chance for the visitors, who now sit 11th.
The result - a third successive clean sheet for Nigel Adkins' men - means Leeds have still never won at the Madejski Stadium.
The hosts had seen midfielder Jem Karacan carried off on a stretcher after just nine minutes, appearing to twist his right knee when challenging Ross McCormack.
Danny Williams and Hal Robson-Kanu tested Paddy Kenny, but the Leeds goalkeeper pushed both strikes away.
Leeds midfielder Rodolph Austin had two opportunities, striking a free-kick over the bar and sending a 25-yard attempt narrowly wide - the only noteworthy efforts for the visitors, Varney's weak effort aside.
Reading centre-back Sean Morrison twice headed high and wide from free-kicks and Nick Blackman saw his goalbound drive deflected wide by Warnock.
But the left-back's night turned sour when he was dismissed for his second bookable offence, and saw Le Fondre capitalise to give the hosts the three points.