The hosts took the lead on 36 minutes when Shkodran Mustafi, on his return from injury, met Mesut Ozil’s free-kick with a towering header.
The Gunners doubled their lead five minutes later when Alexis Sanchez controlled Alexandre Lacazette’s low centre and fired high into Hugo Lloris’s net.
In the second half Sanchez was thwarted by the feet of Lloris, while at the other end Petr Cech denied Eric Dier before Son Heung-min blazed over late on.
Arsenal's 11th consecutive home PL victory took them to within a point of their third-placed neighbours ahead of the 3pm GMT matches.
Arsenal: 26 Nov v Burnley (A)
Spurs: 25 Nov v West Brom (H)