Arsenal boss Arsene Wenger described his side's performance in the 4-0 loss at Liverpool as "not acceptable" and admitted they had been an "easy opponent" for the Reds.
The Gunners were swept aside at Anfield in a way that was embarrassing at times as Roberto Firmino, Sadio Mane, Mohamed Salah and substitute Daniel Sturridge got on the scoresheet.
Asked afterwards about what had gone wrong for his side, Wenger - who opted to drop record signing Alexandre Lacazette to the bench and saw Alexis Sanchez fail to sparkle on his return to the team - said: "Everything.
"I think from the first to the last minute we were not at the level requested for such a game - not physically, not technically, not mentally were we at the level, and we were punished.
"That's basically it. You can analyse the chances we gave away. But I just think overall the performance was not at the requested level."
Arsenal's previous two Premier League matches this season had seen them beat Leicester 4-3 at home, then lose 1-0 at Stoke.
And Wenger added: "I believe in our first two games we looked quite good - our performances were good.
"But today the performance was not acceptable at that level. It is true that today we were an easy opponent for Liverpool."
When asked why the performance had been so sub-standard, the Frenchman said: "That is a question that is very difficult to answer straight away after the game.
"There are some reasons, but I don't think I have too much to comment on that now."
Liverpool manager Jurgen Klopp felt his side's performance was perfect.
Klopp was especially pleased with the intensity his players produced just four days after their emotionally-draining Champions League play-off win over Hoffenheim.
Klopp said: "We played an outstanding game against Hoffenheim and today we did the next step.
"We need to learn we can do things like this every three or four days, otherwise we will have a problem. We wanted to show it today and be spot on from the first second.
"We wanted to show our desire, our greed, our ambitions against a very strong side. We didn't think about winning the game - we thought about the performance. The performance was perfect and the result is the result of the performance."
Klopp surprisingly decided to rest first-choice goalkeeper Simon Mignolet for the game and play Loris Karius. Mignolet was left out of the squad altogether with Danny Ward sitting on the bench.
Klopp admitted Mignolet was disappointed but the Reds boss felt his choice was vindicated.
The German said: "I told Si yesterday. He did not give me a hug and say, 'That is exactly what I thought we should do' but I wanted to do it and give him this rest. I wanted to have Loris in this game.
"He did a lot of good things. He was sometimes too cool but we all need to get used to playing football in close spaces. He did a good job and I am happy with this."
Klopp added that Mignolet remains his "clear number one" and would "100 per cent play" in the next game against Manchester City.
Neither Wenger nor Klopp would say much when asked in their post-match press conferences about potential business in the final few days of the summer transfer window.
Klopp made a joke by deliberately misconstruing a question.
"I was really busy since we started and I would be really surprised if I was not busy in the next few days," he said, before pointing out he was referring to his day-to-day work.
"We will see," he then added with regard to transfers and similarly brushed off questions about the future of Divock Origi and Mamadou Sakho.
Wenger was asked about reports suggest Alex Oxlade-Chamberlain might be allowed to leave.
He said: "That is not the kind of question I can answer after a game like that. What will happen in the transfer market in the next three or four days I don't know."
Asked further about Shkodran Mustafi, he said: "Similar question, similar answer."