Alexandre Lacazette scored twice as Arsenal saw off West Brom 2-0 at the Emirates on Monday night.
Gareth Barry started for West Brom to break Ryan Giggs' all-time Premier League appearance record, while Alexis Sanchez made his first Premier League start for Arsenal since August.
Jay Rodriguez nearly put West Brom ahead in the eighth minute, when he appeared to be taken out by Arsenal defender Shkodran Mustafi in the box.
But rather than immediately appealing for a penalty, the forward got to his feet and struck a shot off the post, and his pleas to the referee then came too late.
The opening goal came in the 20th minute when Sanchez's free kick came back off the crossbar and into the path of Lacazette, and the Frenchman could not miss with his header.
And Lacazette added his second from the penalty spot in the 67th minute after Allan Nyom fouled Aaron Ramsey in the box.