Bournemouth ended 10-man Arsenal's unbeaten start to the season after William Saliba was shown the first red card of his career at Vitality Stadium.
France international Saliba was dismissed inside the opening half an hour, having tripped Evanilson close to the centre circle after being put under unnecessary pressure by Leandro Trossard's poor pass.
It was a situation from which the title-chasing Gunners had already salvaged potentially crucial points against both Manchester City and Brighton, although this time the challenge was to do so for more than 60 minutes.
Their stubborn resistance was finally broken when Ryan Christie fired brilliantly in to the top corner following a clever corner routine with 20 minutes remaining, substitute Justin Kluivert flicking on Lewis Cook's low pass into the penalty area.
Kluivert then put any hope of a recovery beyond Arsenal by confidently converting his penalty nine minutes later, after club record £40m summer signing Evanilson was brought down by David Raya.
Victory ended a dismal run in this fixture for the Cherries, who had lost the last four league meetings by an aggregate score of 13-2, and moved them up to 10th in the table.
But this was a significant blow for Arsenal, who missed the opportunity to go top before leaders Liverpool host Chelsea on Sunday at 16:30 BST, after champions Manchester City visit Wolves (14:00).
BBC