If this is to be the season Fernando Torres finally emerges from the darkness as the £50m striker that Chelsea always hoped he would be then he can give some small measure of thanks to one linesman's bad call last night.
Torres' decisive goal was not simply offside, it was, in the fine margins of the extraordinary pace at which the modern game is played, the figurative mile off. Allowed to stand by linesman Andy Halliday it proved to be the turning point of the game at which Chelsea's comeback finally became impossible for Reading to resist any longer.
This was an impressive fightback from Chelsea from 2-1 behind after half an hour and they deserved a point from the game but the nature of Torres' goal will stick in the craw of Reading's manager Brian McDermott.
The European champions did indeed take the lead and they might have had a couple more through Ramires and Fernando Torres in the first 15 minutes. That was before Reading came back into the game and ended the half, improbably, as the much more dominant side.
What had happened to Chelsea? Even the goal that Chelsea scored was given away cheaply by Brian McDermott's side. Chris Gunter slid in on Hazard on the right side of the box with a tackle so clumsy that it would have been a surprise if the Belgian had not been able to gain some kind of foul. Frank Lampard drilled the penalty home.
Within seven minutes, Reading equalised with a header from Pavel Pogrebnyak. It changed Reading's attitude and soon after John Terry fouled Jobi McAnuff on the edge of the area. Danny Guthrie's free-kick, should not have caused Cech any problems but he made a hash of it. It fell awkwardly for him and the goalkeeper dropped the ball in the goal.
Ineffective in the latter part of the first half, Chelsea faltered for the opening stages after the break. Eventually Roberto Di Matteo replaced Ramires with the Brazilian Oscar and deployed three playmakers behind Torres.
Oscar looked bright but it was Hazard who really got Chelsea going in the second half. They equalised in the 69th minute. Gary Cahill's low drive was struck honestly but it did not have any degree of menace about it. Inexplicably, the Reading goalkeeper threw himself over the top of the ball and gave the home team an easy way back into the game.
The tide had turned and although Chelsea crafted a beautiful winning goal for Torres it should never have been given. Mata worked the ball forward with help from Lampard and Hazard and the ball arrived out left with Ashley Cole. His cross was simple for Torres to tuck away, not least because the striker was well-advanced in an offside position when the ball was played.
Until Ivanovic's late goal, Reading were still in the game. It was not the fourth they were complaining about to referee Mason at the end – it was the third goal that had cost them.