Arsene Wenger bemoaned another "fragile" defensive display in Arsenal's 3-3 draw against Fulham, whose "character" impressed Brede Hangeland.
Wenger accepts Arsenal must learn how to close out games again.
For the second time in a week, the Gunners blew a 2-0 advantage, this time allowing the Cottagers to recover and then lead after early goals from Olivier Giroud and Lukas Podolski had put the hosts in command.
Although Giroud quickly levelled to set up a rousing final 20 minutes, the Gunners - who eventually drew 2-2 in their Champions League tie at Schalke - were unable to fashion a winner, with Mikel Arteta seeing his stoppage-time penalty saved by Fulham goalkeeper Mark Schwarzer.
Wenger knows such costly lapses in concentration at the back must be eradicated if his side are to keep within striking distance of the Premier League's top four.
"We were defensively fragile, were not cautious enough at 2-0 and we let them back into the game because we lacked urgency," the Arsenal manager said.
"We showed magnificent spirit in the second half, but the team has to learn to deal better with this kind of situation.
"There are good ingredients in this team, a good spirit, but we need a bit more defensively when we are leading the game."
Wenger added: "At the moment, we do not get the points we want. Of course, we now do not have to waste any more time, but I still feel there is good potential in our side."
Arsenal will have little time to attempt to rectify their defensive shortcomings ahead of next weekend's north London derby at home to Tottenham as nearly all of the first-team squad will be away on international duty.
England forward Theo Walcott, however, is a doubt for the friendly in Sweden after coming off with an injury to his buttock muscles.
Wenger said: "We have just to keep working, but it will be difficult now this week because everybody goes away.
"What I can do is pray that everybody comes back in good health."
One positive for Arsenal in the past few weeks has been the development of Giroud.
The France forward, signed from Montpellier in a £13million deal over the summer, now has four goals in as many appearances for the Gunners.
Wenger said: "Giroud had presence and won the long balls. He is dangerous and starts to have belief in what he is doing."
Had Giroud elected to take the stoppage-time spot-kick himself, the 26-year-old could well have ended up with the matchball.
Wenger, though, was happy enough with the Arteta's decision.
"We have penalty takers designated, there is no rule that says if you have scored two, you will score a penalty," said Wenger.
"Giroud had missed a penalty in the League Cup, so you know it can happen to anybody - there are not many players who have never missed when they take them."
Despite Arsenal's shortcomings at the back, Fulham also deserved something from the game, if for nothing other than their cavalier approach after falling behind.
Strike duo Dimitar Berbatov and Bryan Ruiz proved a handful all afternoon, with the Bulgarian nodding home with an unmarked header at a corner to begin the fightback on 29 minutes.
Fulham - who are now unbeaten in five - were level through a well-executed strike by Alex Kacaniklic.
Berbatov then kept his cool to stroke the ball past Vito Mannone on 67 minutes after Arteta had pushed over Ruiz, and the Cottagers led 3-2 before Giroud's header soon levelled things up again.
Following the award of a controversial penalty deep into four minutes of stoppage-time after referee Phil Dowd ruled Sascha Riether had handled Andrey Arshavin's cross, Fulham looked like they would be heading back to west London empty handed.
Schwarzer - once a transfer target for Arsenal - secured a well-deserved share of the spoils when he got down to his left and turned Arteta's kick behind.
Centre-half Hangeland told Fulham's website: "We showed a lot of character.
"We want to attack teams and score goals, but as a consequence we are a bit more vulnerable and are conceding more goals.
"But I suppose as long as we keep picking up points, we will crack on and do as best we can."