The winner came in the 72nd minute when Potters substitute Cameron Jerome headed a throw-in - which replays suggested should have been given to the Canaries instead - on to Matthew Etherington, who touched the ball past Elliott Ward before beating John Ruddy at the near post.
It appeared as if Stoke had won the throw only after referee Michael Oliver had been overruled by his assistant, and a fuming Lambert said: "I think it was our throw. He (Oliver) is walking away as if he has given it to us, and he actually raises his hand a little bit as if it is a Norwich throw, and then the linesman has overruled him for some reason."
He added: "Our lads think it is our throw, we are out of possession and then we lose a bad goal. I think it was there for everybody to see that it was a Norwich throw.
"He (Oliver) did admit it to me in the tunnel that he was going to give it to us, but the linesman has overruled him.
"It is frustrating. We never had many chances in the game and never really got going with any fluency.
"This is a really hard place to come - you have to combat that aerial threat, which I thought the lads had done really well. But the throw-in changed the game."
The goal broke the stubborn resistance Norwich had put up for most of the game, Stoke having done virtually all the pressing but unable to convert the few opportunities that came their way, with Ruddy making saves to deny Jon Walters, Dean Whitehead and Peter Crouch in the first half.
"We defended really strongly, as we knew we would have to," Lambert said. "The lads did great defending-wise, but there were never many clear-cut chances for ourselves.
"But that throw-in is ours."
Source: PA
Source: PA