Frank Lampard gave Chelsea an early lead in the 18th minute before Reading equalised through Russian Pavel Pogrebnyak's stunning header. Four minutes later the Royals took the lead thanks to Petr Cech who popped Danny Guthrie's free kick into his own goal.
Defender Gary Cahill equalised for the Blues with a speculative shot but Reading goalkeeper Adam Federici could have done better to push it away.
A frustrated figure throughout the game, Fernando Torres, although slightly offside, probably scored the easiest goal of his career as Chelsea took the lead in the 80th minute.
A last-gasp attempt to save the game saw Reading keeper Federici come forward to help his side steal a point, but Torres pushed the ball forward to Hazard who was unselfish to pass it to Branislav Ivanovic to finish in front of an open goal.
Chelsea's most influencial player Eden Hazard was brought down in the penalty area by Chris Gunter after failing to read the Belgian's trickery. Lampard slotted home his second penalty in two games but seven minutes later former Fulham striker Pogrebnyak headed in a brilliant goal off Garath McCleary's cross.
Chelsea playmaker's Hazard and Mata were at thick of things after Chelsea went down to Cech's blunder at goal. The Czech international goalkeeper handed Reading the lead four minutes later after failing to grab Guthrie's free kick which bounced off his body and ended in the back of the net. Centre-half Cahill smashed an ambitious shot from way outside the box to help Chelsea comeback 21 minutes from time.
Brilliant passing between Lampard, Juan Mata and Torres found left-back Ashley Cole inside the box, but the England international opted to cross instead of going for goal. Cole's calm pass met Torres inches away from goal and the former Liverpool man made no mistake to tap home the winner.
Chelsea began brightly with every forward run looking to threaten Reading's defence but the Royals took a shocking lead within the half-hour mark. The Blues fought back thanks to their playmaker, 32 million Belgian winger Hazard who was involved in every attacking move along with Spanish playmaker Mata.