Georginio Wijnaldum insists Liverpool have not yet proved they are back to their title-winning best.
The Reds are now four points behind leaders Manchester City, who travel to Anfield on Sunday.
Dutch midfielder Wijnaldum told the club website: “I don’t want to say we are back because I think you have to show it every game again. That’s what we have to do.
“We just have to continue to play the way we scored the second goal and try to do it every game. Of course, every game is difficult but when the chance is there to create a chance like this we should do it.
“I think it’s a really bad thing to think that we are back because every game is another situation, another game and another opponent.
“We have to do it again. I think we look at it that way and just try to play the games with confidence.
“I don’t think we should think about that like leading or chasing. We just have to look at it game by game, give everything game by game and then we will see where we will be at the end of the season. I think that’s where the focus should be right now.”
Craig Dawson grabbed a late consolation for West Ham, who remain fifth despite seeing their six-match winning run come to an end.
Captain Declan Rice said: “We all knew what an opportunity it was for us to go out there and put in a performance, knowing Liverpool’s recent form, and knowing the way we’ve been playing, so to not get the win was really disappointing.
“But they’re champions for a reason and they don’t become bad players overnight.”