Jürgen Klopp revealed his frustration after seeing his Liverpool team beaten 3-0 at Watford onSunday afternoon, claiming they lost their minds after the first goal.

Watford moved to within a point of the Premier League’s top four after their fourth straight win and it was difficult to remember a more positive result for them since the Graham Taylor years.

Liverpool have taken one point from the last available nine and the tone was set for them here when the stand-in goalkeeper Adam Bogdan dropped a corner in the third minute, which allowed Nathan Aké to open the scoring.

Klopp argued Bogdan got two hands to the ball and Aké had kicked it illegally from him but it was hard to say the goalkeeper had control of it. What infuriated Klopp, though, was Liverpool’s poor, collective reaction.

“In my opinion you have not to save the ball. You have to have both hands on the ball and he had both hands on the ball, so it’s a foul,” Klopp said. “But I have to say that we made bigger faults than the ref today. Mistakes, fouls, refs, whatever, can happen. That’s football. Our reaction has to be better. We lost our mind after the first goal. We lost our compact formation after the first goal, and we didn’t play easy, as we should have done.

“I would say, hopefully, this is the most disappointing moment in my whole Liverpool FC life, from now. We don’t feel good today, of course, because we came here to do something really different to what you saw. There was a big space between what we wanted to do and what you see, and that’s what we have to fill before the next game against Leicester.

“The start we had, that’s what we’ve got to change and it’s not the first time. This time it was not because we were not concentrated, it was really unlucky. We all know Adam should fix the first ball and he dropped it [but] afterwards it’s not an open ball any more. If they don’t get this first goal today, then I don’t know what happens but, if you see how we reacted, that’s not the best.”

Klopp was asked how he could explain the erratic nature of the performance, in light of the heights that his team had hit in the wins at Chelsea and Manchester City in the league and Southampton in the Capital One Cup.

“I can’t explain,” he replied. “If I could explain this, do you think we would have done it? No, but we work on it. After Southampton everybody thought ‘wow’, and after Man City. But that was one part of the thing we can do, one side. Now we saw completely the other side. Maybe the truth is somewhere in the middle. We have to work so that it’s more on the Man City, Southampton and Chelsea performances.

“For example, on the third goal – Emre [Can] made a good game but he had to pass the ball and he lost it. That’s how football is, you make one wrong decision. The same with Adam. It’s no problem. You only have to react absolutely maximum, much better. That is what we have to work on. The easy games everybody wins. The difficult games we have to win much more often than we have until now.”

Quique Sánchez Flores has Watford in dreamland and the manager was unsurprisingly full of praise for his players. But he maintained top-flight survival was the priority and feet needed to remain on the ground. He also said Odion Ighalo, who scored Watford’s second and third goals, would not be sold in January.

“He is clever, he knows the best option for him. I hope and I believe that he will finish the season with Watford. After that, who knows?”