Arsene Wenger described his 1,000th match as Arsenal manager as a career low after Chelsea inflicted an embarrassing 6-0 defeat at Stamford Bridge.
Wenger was last month called "a specialist in failure" by Jose Mourinho and remains without a victory in 11 attempts against his nemesis after a spectacular implosion and an horrendous error by referee Andre Marriner, who mistakenly sent off Kieran Gibbs.
Wenger did not attend his press conference, but told the BBC: "This defeat is my fault, I take full responsibility for it.
"I don’t think there’s too much need to talk about the mistakes we made. We got a good hiding today.
"It’s one of the worst days (in my career). It’s over after 20 minutes and it’s a long game after that. You don’t prepare all week to experience that kind of experience."
Chelsea were already 2-0 up when Alex Oxlade-Chamberlain handled an Eden Hazard shot and Marriner instead showed the red card to Gibbs, despite his team-mate apparently approaching the referee to admit wrongdoing.
"I believe it was handball but the referee hasn’t seen it," Wenger added.
"But today is a huge disappointment, of course. When you don’t turn up in a game of this stature – nobody takes that easy."
Samuel Eto’o, who went off with a hamstring injury, began the rout and Andre Schurrle added a second inside seven minutes before Hazard converted the penalty.
Oscar added a fourth before the interval and a fifth before his replacement Mohamed Salah netted his first Chelsea goal and the Premier League leaders’ sixth.
Stamford Bridge revelled in the success, roaring "Arsene Wenger, we want you to stay" and "specialist in failure", referring to Mourinho’s taunt last month and the Gunners’ run without a trophy, which stretches back to the 2005 FA Cup.
Understandably, Mourinho preferred not to dwell on Marriner’s mistake as the match was won by then.
The Portuguese said: "We came to kill and in 10 minutes we destroyed (them). Ten amazing minutes, no doubt this game was our game.
"After that, easy. Penalty, red card, 3-0. Easy. But my analysis of the game is about the 10 minutes.
"The penalty was a penalty and the red card was a red card. It’s the kind of mistake that no referee wants to make."