Arsene Wenger accepts everything about Arsenal's performance against Birmingham was "bad" - but maintains it will have served as a "good lesson" in the Gunners' battle for the Barclays Premier League title.
Arsenal looked to be on course for an 11th home win when Emmanuel Adebayor scored from the spot after Stephen Kelly was penalised for a tackle from behind on Eduardo.
However, the Gunners failed to capitalise on their advantage and simply switched off at the start of the second half as Garry O'Connor was allowed to head in from a corner, albeit via a deflection off Cesc Fabregas.
Despite plenty of pressure during the closing stages, there was a distinct lack of a cutting edge to Arsenal's usual flowing football as promising moves came to nothing.
And the resounding 6-0 victory for title rivals Manchester United over Newcastle in Saturday's late kick-off saw the Gunners slip back into second place.
Wenger admits it was a bad day at the office for his team - although they were without Ivory Coast duo Kolo Toure and Emmanuel Eboue, away at the African Nations Cup, as well as Robin van Persie and Tomas Rosicky, both suffering from a virus.
"We were caught in the feeling, during the game, that it would be easy and that is a good lesson for us," said the Arsenal manager.
"We lost a ball we shouldn't have lost and from the corner we weren't sharp enough. Then, after that, we lacked quality in the final third and that was a collective problem."
Wenger declared: "I take full responsibility. The crowd were good, we were bad and I include myself in that.
"That was the poorest game we have played.
"You can never afford to be poor because that's not your ambition.
"We tried, but we lacked creativity, incisiveness and sharpness. It can happen.
"I feel that it is easy to find a rational explanation for days like this - but it is not always the right ones.
"It is one of the mysteries of football that some players haven't played for 10 days and yet they weren't sharp."
Wenger added: "In 22 games this season we have played well in 21 of them. Now we want to come back to what we really are."
Full-back Gael Clichy accepts the team lost focus, and were made to pay a heavy price.
He said: "The boss told us from half-time to be ready from the first minute of the second half. We did not listen to him and now we have dropped two points."
The Frenchman, though, insisted the Gunners still have the character to mount a sustained title challenge over the second half of the season.
"I do not think the mentality is gone," he said. "We know we have the quality to win it.
"We are still there for the title and we are going to show that against Fulham in the next match.
"Let's get on with the job. We have to refocus everyone and move forwards."
Despite his squad now looking somewhat thin, particularly in the centre of defence, Wenger insists he has no intentions of dipping into the transfer market this month.
Although veteran goalkeeper Jens Lehmann - on the bench against Birmingham - elected against a move to Borussia Dortmund, the future of unsettled midfielder Lassana Diarra remains unclear.
One of the reasons for a perceived lack of first-team opportunities in his preferred position this season has been the form of compatriot Mathieu Flamini.
The Frenchman is out of contract at the end of the season, and so is now free to open negotiations with other clubs should he wish.
Arsenal, though, are continuing their own dialogue with the highly-rated 23--year-old, who nearly left the club during the summer.
Wenger said: "I am hopeful on it. I am not concerned.
"Mathieu is free to talk, but the talks [with Arsenal] are ongoing."
