Swansea manager Michael Laudrup was left frustrated after his side failed to deal with the aerial threat of Andy Carroll in their
The striker set up both of Kevin Nolan's goals before being harshly sent off for catching Swans defender Chico Flores accidentally with his arm.
Laudrup said they planned for that threat but were unable to counter it.
"In the first half we knew West Ham were going to play very direct with Carroll and Nolan," Laudrup said.
"We talked a lot about that and the first goal they got from that... that they score in a situation we have analysed so many times before the game is a little frustrating.
"But I think they second goal even more because to give away first a corner and then a goal in injury time in the first half, then you're 2-0 down.
"Even when we had 11 against ten, we saw West Ham the other day defending inside the box at Chelsea and they did the same against us.
"To be fair we had the ball the whole time, a lot of crosses into the box but really not the big chances.
"The last two games, in the FA Cup and the other day against Fulham, we did so much to get back on track but today it was disappointing."
The loss to the Hammers was a sixth defeat in eight Premier League outings for the Swans, who are now only two points better off than West Ham in the relegation places.
Carroll's 59th-minute dismissal could have been a turning point in the game, but West Ham defended resolutely after referee Howard Webb decided to send the striker off for catching Flores with his arm.
Laudrup admitted he did not think the contact between the two men, despite Flores going down clutching his face, was anything out of the ordinary.
West Ham boss Sam Allardyce has already said they would be appealing against Carroll's dismissal.
"I have to say from the bench where I saw it, I think the decision was a bit harsh," Laudrup added.
"I think there was contact but contact like you have a lot of times, but I can't say if he catches his elbow in his eye or whatever it is, if he exaggerated in that way.
"The referee had no doubts, he showed Carroll the red card."
Swansea now have a week to prepare for the south Wales derby against arch-rivals Cardiff City, who are also firmly in the relegation dogfight.