Boss Kieran McKenna felt West Ham didn’t have to work too hard for their goals as the Blues were defeated 4-1 on their first visit to the London Stadium.
Town fell to only their third defeat of the season, the previous two were to top two Liverpool and Manchester City, having previously been on a run of four draws.
"It ended up a disappointing day for us,” McKenna reflected. "I think there was a large majority of the first half was a competitive game, a really good game, we played some good football, and it was evenly fought.
"And obviously we conceded some poor goals at poor times in the game that changed the momentum in the game and it ends up a comfortable victory for West Ham.
"I think we weren’t too far off, as much as the game ends up very, very differently, I don’t think we were too far off it being a good, competitive performance, but there were some moments in there that completely changed the momentum of the game and in the end West Ham were worthy winners and were much better in the second half.”
Defensive solidity had been the hallmark of the four draws but McKenna admitted that mistakes at the back contributed to the loss.
"There were some errors in there,” he continued. "I think West Ham played differently to anyone we’ve played so far, they were very, very direct.
"I think that was what we struggled with really, they were really direct to [Michail] Antonio, he did a fantastic job with the aerial stuff and bringing people into play.
"They went direct to [Tomas] Soucek, probably did better than us on the second balls and it was really those moments that we struggled to deal with the most.
"It was different when the game went to 3-1 and 4-1, then they started to show their individual quality and there were some passages of play but in general the first 60 minutes of the game, it was the direct play we didn’t deal with well enough.
"The goals and chances generally came from those moments and some mistakes from us, some good play from West Ham in those phases and lots for us to learn.”
He added: "If the half-time whistle goes on 30, 35 minutes, which of course in football it doesn’t, I think we would have been happy going in at half-time with still more to come and a good competitive game.
"But they didn’t have to work too hard for their goals, probably the fourth one was good play from them, we didn’t defend it well enough, but other than that the goals came too easily from things which were too simple for them.
"The quality’s really, really high, they’ve got excellent individual quality and they showed that with the goals and the chances that they created.
"If you give them those opportunities, then they were certainly able to capitalise on them.”