New boss Unai Emery secured his first victory with Arsenal on Saturday, with the Gunners battling to an unconvincing 3-1 win over West Ham at the Emirates.
Arsenal have looked just as shaky at the back this season as they did under Arsene Wenger last term, and they went behind on 25 minutes.
Marko Arnautovic was the scorer for the visitors, with the West Ham captain firing past Petr Cech after good work from Felipe Anderson.
While they may have looked far too open at the back, the Gunners were a threat in attack, and equalised soon after via a controlled finish from full-back Nacho Monreal.
Emery has already shown himself to be far more decisive than Wenger when it comes to substitutions, and at half-time, the Spaniard hauled off Alex Iwobi for Alexandre Lacazette.
West Ham continued to have chances to scores, but it was Arsenal who would get the third goal of the game on 70 minutes, albeit in fortuitous circumstances.
Debutant Issa Diop was the unlucky player for West Ham, with the defender deflecting in a firmly-struck Lacazette pass in the box.
The hosts would make it 3-1 late on as West Ham pushed for an equaliser, with sub Danny Welbeck firing home from close-range.
The game would end in a first victory for the Gunners this season.
However, Emery will be well aware of the work needed, particularly in defence, if the north Londoners are to make a dent on the top four this season.
As for Manuel Pellegrini and West Ham, they remain without a point after their first three games of the season.