Bournemouth made the most of two refereeing decisions going in their favour as they dispatched a flat Arsenal side, who had hoped to surge to the top of the table.
The away side predictably hogged the ball in the opening stages but Andoni Iraola's men looked the more threatening, competing fiercely out of possession and when David Raya gifted the ball to the opposition, Antoine Semenyo wasted a handy chance.
Then, with the game moving along at a tepid pace, the pivotal moment - a reckless William Saliba tackle on Evanilson as the Brazilian looked to race through on goal. Referee Rob Jones gave it a yellow but VAR sent him over to the monitor and there was no escaping a sending off.
Arsenal tried not to let the decision break their stride and a few minutes later two summer signings making their first starts of the season linked up for a good chance.
Raheem Sterling found Mikel Merino, who arrived from Real Sociedad to great fanfare, with a cutback but the Spaniard could only hit the side netting.
Bournemouth made the most of two refereeing decisions go in their favour as they dispatched a flat Arsenal side
Justin Kluivert slotted home with an arrogant no-look penalty to heap more misery on the Gunners
The result was a blow for Mikel Arteta's men who hoped to go top of the table
It was soon the end of the unfortunate Englishman's afternoon, however, as the Chelsea loanee was hooked in place of Jakob Kiwior in a defensive reshuffle.
Bournemouth threatened with a couple of solid chances, which fell to Semenyo and Marcus Tavernier, but Raya was up to the task to keep it goalless and Arsenal went in at half-time all square after a spirited reaction.
The home side came out firing and Semenyo soon had his head in his hands once again after he somehow contrived to blaze the ball over the bar from just ten yards out and in bags of space.
As Bournemouth grew into the second period it seemed only a matter of time that they would break the deadlock and take a huge step towards ending a rotten run against the Gunners, stretching back to 2019.
And it came from a corner, Arteta's favourite method of grabbing a goal turned against him.
Lewis Cook fizzed a ball in to the edge of the area, Justin Kluivert dummied it, and Ryan Christie duly fired home to complete the training ground routine.
With the game moving along at a tepid pace, the pivotal moment arrived - a reckless William Saliba tackle on Evanilson as the Brazilian looked to race through on goal. A red card followed
Defensive stalwart Saliba had to go and Arsenal struggled to keep up with Bournemouth
Antoine Semenyo missed a string of good chances as the Gunners held on
But when David Raya was sold short by a Jakob Kiwior pass he committed a costly foul
VAR then came to bite Arsenal once again, as David Raya brought down Evanilson after being sold short by a Jakob Kiwior pass.
Kluivert then slotted home with an arrogant no-look penalty to heap more misery on the Gunners.
Bukayo Saka was a late absentee from the Arsenal teamsheet and, as the away side continued to go down fruitless dead ends, the importance of the Englishman in their frontline became ever clearer.