Manchester City couldn't overcome the pain barrier. As the 32-game unbeaten Premier League run came to an end, there was chaos. Aging, tired legs had to chase – in vain – an opponent full of energy and belief, so rarely seen against the series champions. This time City failed.

Make no mistake, Bournemouth were brilliant, their win was fully deserved and Antoine Semenyo shone. He relegated Kyle Walker to the doghouse, City's captain was left with tainted blood by the Ghanaian.

To be on an equal footing with Walker, he had heeded his manager's request when his fitness was likely well below desired levels. City's starting lineup bordered on the fantastical, but disguised the depth of the casualty list. Even Kevin De Bruyne, who hasn't been seen since September, and Savinho, who left the Tottenham pitch on a stretcher in tears during the week, were on the bench. Neither of them turned on, even when the emergency was imminent.

Bournemouth were determined to catch City off guard. They were part of the competition from the first whistle. Ederson had already been called upon to make a spectacular double save from Semenyo and then Justin Kluivert before scoring began when Milos Kerkez, encroaching on the left, shot past a dozing Phil Foden and set up Semenyo. Josko Gvardiol was dismissed and the Ghanaian's spin and shot clearly outpaced Ederson.

Bournemouth dominated from the start and fully deserved it. City's midfield changes were put under pressure by the energy of their opponents. Aside from a shooting spree by Erling Haaland, City offered little. Arms folded, Guardiola soiled his black leather brogues as he paced the sidelines. At his side, Andoni Iraola, a coach whose promotion prospects make him one of the leading contenders to succeed the Catalan, played every ball.

The victory against Guardiola was history; Bournemouth had never beaten City before in 21 meetings. The last time a point was collected was in 1999, in the third tier, when Joe Royle was City manager and Shaun Goater led the team.

Could it happen? Kerkez continued his eye-catching afternoon with a last-man block when Bernardo Silva had the goal wide open. As Bournemouth dominated the area, home confidence grew and there was jeering when Haaland shot his own attempted shot wide. He appeared to twist his ankle in the process, but saw the first half end with Bournemouth putting together an almost endless succession of passes. After an excellent 45 minutes, their lead could easily have been bigger than a single goal. Few teams have dominated City's midfield like this.

Haaland came on in the second half where Bournemouth took the lead after another quick start. Semenyo picked up a long ball but Evanilson sneaked in and forced another save from Ederson when Mark Travers, Bournemouth's substitute goalkeeper, had not yet come on.

Signals of a possible revival of the city began to sound. Haaland was penalized for jumping highest for a header and Foden went wide with an effort after Matheus Nunes beat Adam Smith with pace and trickery. Walker, who was closest to his manager and had major problems with Semenyo, received constant curt advice from the sidelines and eventually moved to centre-back.

Tempers frayed when Lewis Cook, Bournemouth's top player, eliminated Haaland from a goal down and the City striker returned to action after a long delay. That Bournemouth began to pull away on the hour mark suggested a one-way game, only for the counterattack to be unleashed in devastating fashion. Semenyo shot past Walker again and fed Kerkez, whose low pass reached Evanilson, the striker hammering the ball into the goal.

The lead might have been extended even further when Marcus Tavernier hit the inside of the post. Were they able to hold out? Travers failed to keep out Gvardiol's header from Ilkay Gündogan's cross and there was tension in the final ten minutes. Jérémy Doku's dribbling came into play and the Belgian forced a save from Travers with six minutes left in extra time.

Chaos ensued as Travers fended off another save from Haaland, but the ball somehow failed to cross the line the next time the striker hit the woodwork with his follow-up shot. Foden fired a shot wide but the champions – ragged, exhausted and stunned – could not relent.