By Josh James at Emirates Stadium
Two goals apiece from Olivier Giroud and birthday boy Santi Cazorla gave Arsenal their second 4-1 win in the space of a week.
The Gunners dominated the first half and after Per Mertesacker had hit the bar with a header from a corner, Giroud was more accurate with his head on 15 minutes. He powerfully directed Alexis Sanchez's cross home from eight yards.
For all Arsenal's fluid attacking play though you felt they needed the second goal sooner rather than later. It eventually came on 54 minutes when Cazorla, 30 today, slipped past his man in the area before slotting home.
Giroud added a classy third from Hector Bellerin's cross before Newcastle briefly threatened when Ayoze Perez glanced in a header.
Cazorla sealed the win late on with a 'Panenka' style penalty after Danny Welbeck was fouled in the box.
Setting the scene
Arsenal came into the game buoyed by Tuesday night's emphatic win in Turkey, but needing to pick up their domestic form in order to stay in touch with the teams at the top of the Premier League table.
Neither of the goalscorers against Galatasaray were in the starting line-up however. Aaron Ramsey missed out with a hamstring injury while Lukas Podolski reverted to the bench.
Arsène Wenger recalled Giroud, who was ineligible in the Champions League, as well as Alexis Sanchez, Welbeck and Cazorla, who had all been rested in midweek.
Calum Chambers served a one-game suspension so Mathieu Debuchy filled in at centre half. Kieran Gibbs returned at left back.
Tuesday's teenage debutant Ainsley Maitland-Niles kept his place on the bench, alongside Francis Coquelin who has been recalled from his loan spell with Charlton on Friday.
As for the visitors - who had lost just one of their last 10 - there was a first start for 21-year-old goalkeeper Jak Alnwick after his substitute appearance in their win over Chelsea last weekend.
Newcastle's two-goal hero in that game Papiss Cisse was restored to the starting line-up, while Mike Williamson replaced the suspended Steven Taylor at the back.
Arsenal started brightly and took the game to Newcastle early on. Hector Bellerin and Alexis were linking up well on the right flank, and in the first minute Alexis fed Welbeck inside the area, but his cross was charged down by Jack Colback.
Mertesacker hit the woodwork from Cazorla's corner inside the opening 10 minutes. The big German did well to divert the ball goalwards at the near post, but it rebounded against the underside of the bar, bounced in front of the line and the danger was cleared.
Arsenal were full of attacking intent though, and after a quarter of an hour they got their reward. Alexis got away down the right again, swung in an inviting cross and Giroud rose majestically above Daryl Janmaat to planted his header beyond Alnwick from eight yards.
Moments later Welbeck had a goal disallowed for an apparent foul in the build-up.
Arsenal continued to run at the visiting defence at every opportunity. The pace of the forward players was causing real trouble for United, not to mention the speed of right back Bellerin. The teenager cut a swathe through the Newcastle side with a determined run from his own half, eventually earning a corner.
Welbeck was next to go close, lathing onto Alexis's scooped pass into the area but his volleyed effort went just wide.
It was largely one-way traffic, but with 10 minutes remaining in the half Arsenal survived a scare. Yoan Gouffran's header from a free-kick was parried by Wojciech Szczesny, the ball fell to Cisse in front of goal but his follow up was also well blocked by the Polish keeper, and Arsenal scrambled the ball away.
As the half drew to a close a clever free-kick from Alexis picked out Cazorla 25 yards from goal, but his first-time strike was deflected wide.
The first-half was slow to get going in comparison, but Cazorla - on his 30th birthday - lit up the evening with a superb finish on 54 minutes.
Alexis released the Spaniard inside the box. His first touch took the ball delightfully away from Fabricio Coloccini, while his second clipped the ball beyond Alnwick and into the net from an acute angle.Just four minutes later Arsenal increased their advantage, with Giroud's second of the game.
Bellerin - a livewire all evening - skipped down the right wing, sent in a low cross and Giroud deftly finished at the near post with his left foot. It was the Frenchman's fifth goal this season, and this was only his fourth start of the campaign.
Next Alexis hit a free kick straight into the wall after Alex Oxlade-Chamberlain was crudely brought down just outside the area. Cazorla then drove his free-kick from near the byline across the face of goal.
Arsenal were well on top, but Newcastle checked the momentum with a goal of their own on 63 minutes.
Colback sent a low free-kick into the area and Perez stole in to glance a header past Szczesny.
The clean sheet had gone but the Gunners soon sought to re-exert their authority.
Welbeck won the ball well inside the Newcastle area and the ball eventually fell to Oxlade-Chamberlain on the edge of the box. His skewed shot found its way to Gibbs whose first-time volley flashed wide.
Newcastle were starting to see more of the ball, but with 12 minutes left Alexis pounced on a loose pass in his own half to launch a counter attack. The Chilean and Welbeck had a two on one against Coloccini. The Argentine defender stood his ground though and dispossessed Welbeck on the edge of the area.
Arsenal were awarded a penalty with two minutes remaining when Paul Dummett felled Welbeck in the box.
Cazorla stepped up and cheekily chipped home the spot kick.There was still time for 17-year-old Maitland-Niles to make his Premier League debut, four days after his Champions League bow.
It was an unforgettable week for him personally, and a very satisfactory end to a fine week for the Gunners too.
Referee: Lee Mason
Copyright 2018 The Arsenal Football Club plc. Permission to use quotations from this article is granted subject to appropriate credit being given to www.arsenal.com as the source.