In a match of few chances, Pierre-Emerick Aubameyang netted the decisive goal in the second half to hand the Gunners the perfect start after a summer of upheaval.
Newcastle had their moments in the North-East but their second half performance offered little encouragement to the club's supporters, leaving Steve Bruce with much work to do going forward.
Despite both teams making major additions during the transfer window, just one - Newcastle's Joelinton - was included from the opening whistle as each of Bruce and Unai Emery opted to keep the majority of their signings in reserve.
A quiet start to the contest followed, with the Magpies the first team to go close in the 17th minute as Joelinton glanced a header wide of the far post after meeting Matt Ritchie's cross.
Jonjo Shelvey then struck the outside of the post with a 20-yard volley, but Arsenal should have taken the lead at the other end, only for Henrikh Mkhitaryan to blaze over from 12 yards after positive work from Nacho Monreal.
The Magpies hit back with Joelinton holding off the attention of three players before volleying straight at Bernd Leno, while Aubameyang did similar at the other end as Martin Dubravka saved well at his near post.
Despite the lack of urgency from their respective sides, both managers resisted the temptation to make immediate changes, and it led to the game continuing to be played at one pace after the restart.
However, Arsenal made the breakthrough just short of the hour mark. Space opened up for Ainsley Maitland-Niles down the right-hand side and after the full-back found Aubameyang, last season's top goalscorer took a touch before flicking the ball over Dubravka from 12 yards.
Bruce reacted by introducing summer signing Allan Saint-Maximin but despite adding energy down the flank, the winger's intensity was not being matched by his teammates.
The former Nice man saw a low effort kept out by Leno but that was as good as it got for the Magpies, leaving Arsenal to coast through the closing stages of the contest.
In truth, this was the perfect day for Emery as he witnessed his team keep a rare shutout on their travels, while the Spaniard also knows that he still has several players to integrate into the starting lineup over the next few weeks.
NEWCASTLE UNITED (3-5-1-1): Dubravka; Lascalles, Schar, Dummett; Manquillo, Hayden, Longstaff (Saint-Maximin 67'), Shelvey (Willems 54'), Ritchie; Almiron; Joelinton
ARSENAL (4-2-3-1): Leno; Maitland-Niles, Chambers, Sokratis, Monreal; Guendouzi, Xhaka; Nelson (Pepe 71'), Willock (Ceballos 64'), Mkhitaryan (Martinelli 84'); Aubameyang