Newcastle were the first to have a sight of goal, when Jamaal Lascelles had his header tipped wide by Petr Cech.
Arsenal took control of things though, and Alexandre Lacazette in particular was looking dangerous. He had a shot blocked by Florian Lejeune, and then Hector Bellerin's follow up was also closed down well.
The home side were utterly dominant. Alexis Sanchez had a snap-shot, but it was always rising and sailed high over the bar.
Ainsley Maitland-Niles started at left-back for Arsenal and looked very impressive, especially going forward. He beat three Newcastle players before rifling a shot against the side netting. Newcastle had totally retreated into their own half.
Their resistance was broken eventually. Bellerin fired a cross into the box, which Newcastle ultimately managed to clear only as far as Mesut Ozil, who struck a superb left-footed volley into the far corner. An excellent finish.
Sanchez then picked out the marauding Bellerin with a brilliant diagonal pass, but the Spaniard's volley was not as accurate as his German teammate's.
The Magpies failed to muster any sort of attacks, and seemed completely devoid of any confidence.
Granit Xhaka and Sanchez tried to double the Gunners' lead, but both saw their long-range efforts go wide of the post.
Rob Elliot did very well at the beginning of the second half to deny Alex Iwobi, and even better to stop his second attempt, as Arsenal looked to kill off the Magpies.
Murphy looked the most threatening for his side, he cut in from the left, evaded two challenges, before forcing Cech into a fine save.
Jack Wilshere almost finished things off when substitute Olivier Giroud did brilliantly to knock the ball down to the midfielder, but he fired straight at Elliot.
Dwight Gayle was introduced for the final quarter of an hour, and he almost provided Joselu with his fourth goal of the season. The former Stoke City man's shot was deflected inches wide of the post. Very unlucky.
Matt Ritchie also came on for the visitors, and he set up Ayoze Perez with a brilliant cross, but his header sailed wide of the far post. You cannot say they weren't trying.
Joselu worked his socks off for 90 minutes, but his ambitious overhead kick at the death lead to an Arsenal free-kick in the penalty area.
It just was not to be for a dogged Newcastle side. The slide is worrying, but Rafa Benitez will take some pride in his team's performance. They HAVE to get something at West Ham next weekend.