After a goalless first half, which mirrored what was happening at White Hart Lane between Tottenham and Sunderland, it took Arsenal less than ten minutes into the second half to claim the winner which guaranteed their top-four finish ahead of their arch-rivals.
Newcastle failed to deal with a Theo Walcott free-kick, and it fell for Laurent Koscielny just six yards out and he volleyed home with great aplomb.
That goal was enough to mean that the result in north London was meaningless, although Tottenham did do their part as Gareth Bale fired home to win it for them but Arsenal did their job to claim a top-four finish by just one point.
Arsene Wenger's side were clearly a bit nervy from the start, more concerned with not conceding rather than scoring, although the first opening came for Walcott when he fired over six minutes in.
But with Newcastle owner Mike Ashley willing to share out £1million between the club's non-football staff if they won, the home side did have something to play for, and Papiss Cisse came close to converting a cross from Mapou Yanga-Mbiwa, who was playing as a makeshift left-back, but it flew just over.
Arsenal's gamble of playing Mikel Arteta did not work as he was forced off on the half-hour with Alex Oxlade-Chamberlain coming on, and they took time to adapt to the change.
Newcastle did have glimpses of goal with Yohan Cabaye testing Wojciech Szczesny before Hatem Ben Arfa blazed over the bar when he should have done better after finding room in the box.
One of the highlights of the first half was just before the break on 37 minutes when Newcastle's home fans gave a minute's applause to their number 37 - the retiring Steve Harper.
But he almost had a moment to forget just 30 seconds into the second half. His poor clearance presented Walcott with a good chance, but the veteran shot-stopper saved well and Steven Taylor got back to clear.
On 52 minutes a Walcott free-kick was not dealt with and it dropped to Koscielny off Yanga-Mbiwa and the Arsenal centre-half volleyed past Harper from close range to send the travelling fans into raptures.
To their credit Newcastle did not just cave in and they pushed on looking for an equaliser but Koscielny and Per Mertesacker stood firm at the heart of Arsenal's defence. Both were on hand to put a block on Yoan Gouffran inside the six-yard box, whilst Ben Arfa fired one just wide from long range.
The late goal at Tottenham made for a nerve-jangling finish, although it was Arsenal who should have doubled their lead as Walcott broke clear in the final minute, and he beat Harper but his shot cannoned back off the post.
But, despite their efforts Newcastle could not find a way through as Arsenal claimed the win which means the Magpies finish a lowly 16th, whilst the Gunners take their place at Europe's top table once again as their qualification for next season's Champions League was confirmed.