Norwich boss Alex Neil lamented familiar failings as Diego Costa's goal from an offside position proved decisive in Chelsea's 2-1 win at Carrow Road.
The Canaries conceded after 39 seconds to Kenedy's fastest goal of the Premier League season so far and then Costa's strike before half-time should have been ruled out for offside.
But assistant referee Michael McDonough failed to flag and referee Lee Mason awarded the goal, despite protests as Norwich lost for the seventh time in eight Premier League games to fall into the relegation zone.
"He is offside. I've seen it back on the video," Neil said. "You would expect the officials to get it right. It's disappointing they don't get it right. They'll be disappointed they didn't get it right. But the linesman's called it how he saw it.
"It's not as if he's two or three yards offside. He's probably a yard, half a yard. You'd like to think he would've got that one correct, but when you're down at that bottom end those wee bits of fortune that you look for just don't come your way."
Neil felt wronged and made his point to the officials clearly at half-time.
He said: "I made him aware at half-time that he got it wrong and he was offside. The guy's made an honest call and got it wrong. It happens. I'm not going to stand here and lambast him for that.
"We're disappointed, really frustrated, but it is what it is."
Norwich ensured Chelsea never truly had a grip on proceedings and had the better of the second half. Cameron Jerome hit the bar early in the second half and Nathan Redmond pulled a goal back 22 minutes from time, but it was too little, too late.
"Defensively for the first goal -- a minute into the game -- their left-back scoring when I've got a back five and sitting midfield player is a real source of frustration for us," Neil added.
"It's probably been the story of our last few games. We had better opportunities than Leicester, lost the game. West Ham we were 2-0 up, looking comfortable and we managed to draw. Liverpool we were 3-1 up and managed to lose the game.
"I don't think when that's a continuous thing that keeps happening, I don't think it boils down to just luck. Quality shows and at times we missed opportunities we should've taken."
Midfielder Alex Tettey went off in the first half for a precautionary X-ray on a leg injury and Gary O'Neil required stitches to a two-inch gash on his head following a clash with Robbie Brady, who lost two teeth and chipped another.