Norwich manager Chris Hughton was once again left ruing the inability of his players to convert their chances as the Canaries were beaten by two late West Ham goals.
Summer signing Gary Hooper spurned the best of the visitors' chances at Upton Park as Norwich continued to come up against Adrian, a goalkeeper in fantastic form.
Robert Snodgrass and Alex Tettey also saw decent efforts kept out by the Spaniard before James Collins headed home a Mo Diame cross with six minutes remaining, paving the way for a 2-0 win.
As Norwich poured forward in search of a deserved equaliser, second-half substitute Diame was released into the Canaries' half and finished the game off deep into added time.
The win moved the Hammers up to 10th in the Barclays Premier League and left Norwich down in 16th - with Hughton bemoaning his side's missed chances.
"I am very, very frustrated," he said.
"When you come here, you know you'll be up against a direct and physical game and you have to match them. For nearly all the game we were able to do that but you rely on getting a little release by scoring goals.
"No-one can say we didn't attempt to get into goal areas and didn't create chances. It is a bit too familiar, creating chances and not putting them away. We put more pressure on ourselves.
"The first goal is a ball we dealt with all game and on that one occasion we didn't. When you don't get the lead that you think you deserve, you are always under pressure. It's the first goal that hurt us and the missed chances."
England goalkeeper John Ruddy was culpable for Collins' crucial opening goal as he rushed from his line only to see Diame's cross float over his head.
But Hughton refused to lay the defeat at the door of his goalkeeper, who had faced a largely quiet opening 84 minutes of the game,
"I'm never one to apportion blame but it's the type of ball we dealt with very well all game," said Hughton.
"When you play West Ham you have to deal with a lot of them and we did it well. No doubt the better chances fell to us. There was so much good about our performance.
"The (opposition) keeper's made some good saves and unfortunately in our last two away games both keepers have put in man-of-the-match performances. It shows we're creating chances. But we've got to look at ourselves."
West Ham manager Sam Allardyce has now seen the club enjoy three consecutive Premier League wins for the first time since the end of the 2006/07 campaign, turning around early-season form as they seek to remain in the top flight.
"It is just delightful," Allardyce said.
"An outstanding victory and a hard-earned win - 13 points from six games is a terrific run of form considering where we were and the trouble we were in.
"Even 10th might not be out of trouble - we have to continue and get more results.
"It's a great end to an important run of fixtures. If Norwich continue like that, they will have no problems. They were very good and gave us a good game."
Allardyce was again left singling out the heroics of goalkeeper Adrian, who kept his fourth clean sheet in succession to set his side up for another valuable three points.
"Our goalkeeper kept us in the game," Allardyce said.
"We scored late, when it is hard for anybody to come back into it - his reward was us winning it."