Norwich manager Chris Hughton was left frustrated after “big decisions” went against his team in their 2-1 defeat at West Ham - which was a fourth straight Barclays Premier League loss.
Both sides went into the New Year's Day encounter needing a boost following a poor run of form, with the Irons last win coming against Chelsea on December 1.
The home side were given an early opportunity to take command when referee Mark Clattenburg spotted a shirt pull by defender Ryan Bennett on Winston Reid, and Mark Noble converted the controversial penalty.
Although Norwich midfielder Robert Snodgrass rattled the woodwork with a free-kick, Joey O'Brien crashed home a second goal on 26 minutes, which proved enough to secure the Hammers a morale-boosting victory ahead of next weekend's FA Cup tie against Manchester United.
Russell Martin netted a well-taken volley for his third goal in two games during stoppage time, but it was scant consolation for Hughton.
Snodgrass later posted a Tweet claiming "the referee kills the game. £gamesgone" - and while accepting there was cause for a foul, Hughton felt the penalty award was soft, as well as highlighting other calls which went against the visitors.
"There is frustration with the big decisions, the key decisions in the game did not go in our favour," said Hughton, who confronted Clattenburg as he left the pitch at both half-time and following the full-time whistle.
"We accept Ryan Bennett had hold of the lad's shirt, but I also saw Reid's forearm in Ryan's chest. They are very close, he is not pulling Reid so he cannot get away, it is something you see game in and game out right throughout the country.
"On almost every occasion you do not see a penalty, particularly when it is so early in the game, so I was very surprised when he gave it.
"I also don't accept it was not a foul on Alex Tettey leading up to the second goal and certainly was a handball in the first half and then Harry Kane had a penalty claim, so we were on the wrong end of some poor decisions."
After a 10-match unbeaten run which pulled Norwich away from the relegation zone, Hughton's side have endured a miserable run over the festive season, beaten at home by both Chelsea and Manchester City as well at West Brom.
The Canaries, however, still have daylight between themselves and the relegation zone.
"Nobody has really given us a beating and they have all been really close games," said Hughton.
"We have to be at our best to get results and we have been close in the last four games.
"For us now it is about getting back to winning ways."
The Irons, meanwhile, kickstarted their campaign following a run of just two victories in the previous 11 outings.
Carlton Cole had missed a great chance to make it 3-0 when he blazed over from close range before the break, while Ricardo Vaz Te also saw his second-half header come back off the post.
West Ham manager Sam Allardyce feels his side are moving in the right direction.
"It's a shame the score didn't reflect the performance. The win was very important but it should have been about 4-1 or 5-1 based on the amount of chances we created and missed," said Allardyce, who hopes to have striker Andy Carroll available again from injury by the end of the month.
"It was an outstanding performance under the circumstances and an outstanding result."