The morning of the game sparked more rumours of Alexis Sanchez's potential destination in January and with a move to Manchester United supposedly edging ever closer he was left out of the Arsenal squad entirely for their trip to Bournemouth.
The Gunners on the other hand were left effectively condemned in the sixth position, five points behind fifth placed Tottenham Hotspurs who secured a 4-0 emphatic win over Everton on Saturday.
The win saw Bournemouth climb to thirteenth on the Premier League table with 24 points.
Arsenal must now dust themselves down as they look to get back to winning ways in the Premier League when they take on Crystal Palace at The Emirates next weekend.
After a goalless first half at the Vitality Stadium, Hector Bellerin broke the deadlock with a scruffy finish after he was put through on goal by Alex Iwobi's impressive through-ball in the 52nd minute.
But with a much-needed three points there for the taking, Arsenal capitulated against their spirited hosts.
Alexandre Lacazette, a player who has been low on confidence of late started up top - and with Sanchez departing the Frenchman now has an even bigger onus on him to become Arsenal's main goal scorer, something he couldn't manage on the day.
The 25-year-old was key to Bournemouth's comeback, though, scoring the first after a magnificent cross from Fraser and then providing the assist for Ibe's victor.