Alexandre Lacazette is looking like the real deal thus far for Arsenal, and the French striker continued his contributions for the Gunners during the first half.
While it was Alexis Sanchez that was narrowly denied a stunning free-kick finish seconds earlier, Lacazette was there to finish off the chance for his third goal of the season.
The Gunners sat on the front foot for much of the opening stanza, but West Bromwich Albion did have a bit of reason to be frustrated in the ninth minute.
Baggies forward Jay Rodriguez looked to be taken down by Shkodran Mustafi as the former tried to cut back towards the top of the Arsenal penalty area, however, referee Bobby Madley was having nothing of it.
Rodriguez had a second big opportunity to give the Baggies a goal in the 38th minute as Nacho Monreal cleared his header off the goal line.Follow @MattReedFutbol