Declan Rice proved West Ham's matchwinner on the day.
Emery lamented, "I think the result is a bad one. We lost a great opportunity to take three points and get closer to Chelsea and the other top-four teams. But we lost. We wanted to do a better match but we couldn't control the match like we wanted to. Looking at the chances in the 90 minutes for them and us, I think maybe the result is not what we deserved. In the gameplan, in the control, we need to improve our ideas.
"We could not do that. We didn't concede a lot of chances but we conceded metres on the pitch and these metres gave them a lot of corners. From one corner, they scored, and then the match changed.
"We needed to attack more and better but today, defensively we needed to work well. We created chances but it wasn't enough to win. Maybe in the first 20 minutes when we created some chances, that was the moment where we thought we could win the match, but then after it was difficult because we didn't impose all the things we wanted."