Frustrated Norwich get sinking feeling after referee blunders
Norwich City's fear of returning back to the Championship was accelerated by the fastest goal of the season, another that was clearly offside and one of the more remarkable refereeing mistakes of the campaign - plus a terrible miss of their own.
It hurt that they played well but could not take their chances. It hurt even more that Diego Costa's offside goal proved decisive.
For Chelsea the revival continues and it is now 11 unbeaten under Guus Hiddink in the Premier League as they move up to eighth in the table.
Norwich were behind after 39 seconds as Eden Hazard collected possession and was allowed to run from deep before finding left-back Kennedy, who drilled a powerful low left-footed shot across John Ruddy and into net.
For Norwich there was already a sense of apprehension but Wes Hoolahan and Cameron Jerome combined well to carve out a couple of sights of the Chelsea goal.
The home crowd became incensed when Gary Cahill's clear backpass went unpunished and their feeling of injustice was compounded when Costa scored Chelsea's second from an offside position. It came as Hazard flicked the ball through and Costa had drifted ahead of the defenders but was allowed to go on and beat Ruddy.
Just as Chelsea had scored in the first minute of the first-half so they had done in the final minute also. "You're not fit to referee," chanted the home fans.
Hoolahan put Jerome through again after the break but from close-range he somehow hooked the ball up onto the bar and over. He had to score.
The Irish midfielder's probing eventually paid dividends when his fine pass put through Nathan Redmond, who slammed the ball high into the net to beat Thibaut Courtois at his near post. Suddenly there was belief but when Gary O'Neil went off for treatment after an sickening clash of heads with Robbie Brady and Willian their momentum was stalled.