Arsene Wenger knows full well Arsenal will not win anything this season if they continue to fail to deliver when it matters most.
The Gunners looked on course to go top of the Barclays Premier League after they romped into a 2-0 half-time lead over north London rivals Tottenham at Emirates Stadium. But as Arsenal's focus dropped, Spurs rallied to produce a remarkable fightback to win 3-2 and record their first away win over their old enemy since 1993.
Although the damage of a third home defeat was limited by Chelsea's 1-0 loss at Birmingham, Wenger said: "It is painful, but more because we had an opportunity to go top of the league that we did not take, and a mature team, you want them to do it. That is what hurts the most, because that is what is needed if you want to be successful and win trophies."
Arsenal are now down to third place, two points behind Manchester United who are behind Chelsea only on goal difference.
Wenger continued: "We delivered quite a good game and created many chances.
"What is much more difficult to understand is that we lack some basic concentration on facts in the game where you can be punished. When you want to win, that cannot happen."
Just how Arsenal contrived to throw away what could yet prove to be three priceless points mystified both Wenger - who at one stage threw his water bottle to the floor of the technical area in disgust - and Gunners fans alike.
The hosts - beaten 1-0 at home by Newcastle a fortnight ago - were in cruise control following goals from Samir Nasri and Marouane Chamakh, but took their foot off the gas at the start of the second half when Spurs had reorganised following the introduction of fit-again England striker Jermain Defoe, making his first appearance since early September.
Gareth Bale started the fightback on 50 minutes with a neat close-range finish, before an inexplicable handball by Arsenal captain Cesc Fabregas from a free-kick gave away a penalty, which Rafael van der Vaart converted.
There was, though, one more sting in the tail when, with five minutes left, Younes Kaboul headed in a dramatic late winner.