Slaven Bilic was disappointed with his West Ham players after gifting what he felt were two cheap goals against Chelsea on Monday night.
Eden Hazard and Diego Costa scored in either half as the Blues opened up a 10 point lead at the top of the table, with a Manuel Lanzini strike late on proving nothing more than a consolation.
Speaking about the match, Bilic said: “I’m happy with the way we started. Then we made that mistake.
“We started well in the first half, and then to make such a mistake that led to their goal when we had our centre backs and everybody in their box,” said the Croatian. “We should have put the ball back into their box. We didn’t and they scored from a counter-attack.
“And then their second goal, from our side was a cheap one.
“The story is very simple. If you want to beat Chelsea, they have to make the mistakes for you to score goals and not the other way round. [Otherwise] you have very little chance.
“We scored a goal which was good, and we could have scored more, but in the second-half every attack they had with their pace and quality looked very dangerous,” Bilic said.
Speaking about Chelsea’s second goal, he added: “It’s a set piece for us and we have enough players at the back and then we get the second ball in a good position to put the ball in but we didn’t.
“We lost the ball in a space where you can’t afford to, especially against them because their pace in the transition is scary.”
Asked to assess if the title was Chelsea’s to lose, he added: “They look very serious and I can see them staying at the top with the quality they have, and with how solid they are and how concentrated they are.”