The victory may have been the most important thing as Arsenal squeezed past Olympiakos in the Champions League, but if they continue to defend as they did at the Emirates, their season will be as good as over before Christmas.
Despite the result, it is worrying how easily Arsenal were carved open at times and how much space they offered Olympiakos.
Against better opposition they would have conceded a handful again.
Looking back through relatively recent history, the Arsenal team was built around a solid defensive foundation, particularly during the nine-year reign of George Graham.
However, 14 goals conceded in their last four away games is a far cry from days gone by and does not bode well that they will get any kind of result from their trip to North London rivals Tottenham.
Defending set pieces have been a major problem and even giant new arrival Per Mertesacker has failed to help improve the situation.
In fact, Mertesacker has looked far from the dominant figure in the air all around, which is a surprise given his frame, while his lack of pace on the turn is a worry.
Fellow new arrival Andre Santos has added some useful adventure to Arsenal’s attacks, but he has also looked suspect at the back.
Meanwhile, the troubles of those around him have also had consequences on the form of Bacary Sagna, whose form has remarkably dipped from last season.
Things will not get any easier against Tottenham, with Thomas Vermaelen still sidelined and doubts over the fitness of Laurent Koscielny and Johan Djourou.
Seven of the last eight North London derbies have seen over 2.5 goals scored, including all of the last five and the manner of Arsenal’s defending means that this is virtually a banker to happen again at White Hart Lane.
It is 8/13 in the Premier League odds that a minimum of three goals are scored, with Tottenham looking the better bet at 5/4 to take the three points and secure a fourth straight top-flight victory.