Pep Guardiola laments fitness troubles as Bournemouth end Manchester City's winning streak
Pep Guardiola's men had not lost in the league since their defeat to Aston Villa on December 6th last year but from the first moments on the south coast Andoni Iraola's side looked a match for them.
The Cherries struck in each half through Antoine Semenyo and Evanilson to take a firm grip on the match.
It looked at times as though Bournemouth would run away from City. Marcus Tavernier struck a post at 2-0 to leave the visitors clinging on by their fingertips, before Josko Gvardiol set up a nervous finish when he headed in Ilkay Gundogan's cross.
Guardiola said the champions were struggling with their lengthy injury list.
"It is what it is. We have few players with a lot of minutes and a lot of players with no minutes - the balance is a bit uncomfortable," he told the BBC.
"We played good against Spurs but today we could not handle their intensity that they had and that's why we lost the game."
A depleted City were beaten for the first time this season in any competition in the League Cup against Tottenham in midweek.
Guardiola had told his players they would need to play through the pain and there were starts for Gvardiol, Kyle Walker and Manuel Akanji, all of whom had been doubts.
Kevin De Bruyne was fit enough only for the bench where he was flanked by three teenagers without a Premier League appearance between them.
John Stones and Ruben Dias were absent from the squad entirely and City could have used the central defensive pair during a first 20 minutes in which Bournemouth attacked fearlessly.
The visitors fell behind in the ninth minute when Milos Kerkez cut the ball back to Semenyo who, having trodden on the ball in his haste to shoot, recovered to turn Gvardiol and angle a finish wide of Ederson.
Kerkez produced an outstanding block tackle on Bernardo Silva to preserve the lead then Erling Haaland dragged City's best chance of the first half wide.
Semenyo and Justin Kluivert were a constant threat to the visitors' defence.
The outstanding Kerkez was again the architect of the second goal, rocketing clear of Walker down the left and crossing to where Ake and Gvardiol had abandoned Evanilson in the middle, giving the Brazilian room to pick his corner.
Tavernier fired against the inside of the post as Bournemouth threatened to overwhelm City.
Gvardiol's header offered late hope and City might have levelled had Mark Travers not beaten Haaland's effort off the line in stoppage time.
Phil Foden then fired inches wide with the final kick as Bournemouth held on.
City are two points behind Liverpool, who came from behind to beat Brighton 2-1 at Anfield but third-placed Arsenal lost 1-0 at Newcastle.