Frank Lampard fumed at his Chelsea side’s litany of defensive mistakes that once again cost the Blues vital points in the race for Champions League qualification.
Chelsea entered the occasion on a red hot run of form, but lax defending cost them the chance to move up to third in the table.
The defeat added further pressure on their quest to secure Champions League qualification for next season, and Lampard bemoaned the costly mistakes his side made after the match.
Speaking to BBC Sport, Lampard said: “It happens, it is the Premier League and if you make mistakes like we did, we dominated the game in terms of possession, but make mistakes and teams will hurt you.
“I’m not happy with any of the goals. You don’t get given victories for scoring two goals, you have to be better than that.
“There were moments they counter-attacked, which we knew they would.
“There were details in the game which we knew but we lost because we didn’t get them right.
“It is why we are fighting for top four not one or two, because we don’t get things right as much as the big boys do.”
“I am not happy with tonight but at the same time we are two points ahead of Manchester United, who have been going great for some time.
“If you don’t get details right in big games, you’re going to drop points.
“I think at times we have played really well this season. As a group we need to find more consistency.
“We have to defend the moment better. Against West Ham you have to make recovery runs. That is the bit we got wrong.”