When does a slip-up become a burglary? Before the game, Pep Guardiola was asked this question and referred to Manchester City's outstanding run of success. Now the last three games under him have been lost for the first time since April 2018, so Saturday's trip to Brighton will certainly be about stopping the decline.

Two years ago, Rúben Amorim's Sporting lost 5-0 in a great city show full of power football. This final home game for the new Manchester United coach ended with him becoming the “new Ferguson” for a section of the Red Devils faithful, as he predicted if their city rivals were to fail.

The 39-year-old achieved this by coaching Sporting on the quick counter-attack and then ensuring it was executed expertly as City became opponents.

City still have seven points, Amorim leaves with ten points and determines Sporting's Champions League fate. All this with the 3-4-3 shape he brings to United when he starts work on November 11th.

“Sweet Caroline” came on, the José Alvalade was almost sold out and Amorim's home swansong got off to a terrible start.

The players had been busy exchanging passes before Phil Foden stole possession from Hidemasa Morita. Sporting pulled back so City's playmaker advanced into the box and Franco Israel shot past.

This was a welcome relief after City's defeats to Tottenham and Bournemouth. But his fragility was revealed during a Gyökeres raid in which he was released. As Ederson advanced, the Swede hoped to beat the goalkeeper but shook him up and the ball was collected.

Guardiola has spoken about his running injury and how it is all part of the challenge of this season. With Rúben Dias and John Stones on the injured list, the manager gave Jahmai Simpson-Pusey a full debut 24 hours after the defender turned 19, and Gyökeres' next move was to attack him down the left channel, the Boy from Manchester was tough enough to overcome the challenge.

Previously, City threatened with two Foden corners and two attempts from Erling Haaland. Israel made a flying save on the first shot, and the Norwegian's weaker right foot missed the goal on the second shot.

City had the Portuguese champions under control as usual: they monopolized the ball and forced them to live in duels. As Israel dawdled and played from the back, Haaland almost ambushed him. The next time Sporting tried the trick, Savinho grabbed the ball and City had them by the jugular, in a sequence that resulted in another Foden corner that Josko Gvardiol narrowly missed.

Equally impressive was a move from the back to the front, with Mateo Kovacic playing at half-court and right-back Rico Lewis slipping inside to allow Savinho to gallop through. Result: a cross for Haaland and another Foden corner.

His next ball landed on Haaland's head and although he beat the flying Israel, the ball was cleared off the line. City were a relentless force, intimidating their hosts with percussive passing. Foden popped up on the left and hit a shot that Haaland volleyed away and Israel parried away.

The ball retention rate of 72.9% was the competition in microcosm. City was in shooting training mode. Bernardo Silva fought through and shot to beat Israel, but the attempt went wide.

Gyökeres then broke away – after a pass from Geovany Quenda – and when he reached the penalty area, he held off Simpson-Pusey and formed a wonderful sand wedge over Ederson to make it 1-1.

Sporting's next break behind City's high line almost resulted in a copy, but Francisco Trincão's composure failed and the striker shot wide.

City melted when Maximiliano Araújo fell behind to Pedro Gonçalves' ball practically from the start of the second half and beat Ederson. The stunned visitors were soon shocked. Gvardiol was the culprit, foolishly upending Trincao and the referee, Daniel Siebert, awarded a penalty. Gyökeres shot the ball past Ederson and the stadium was full of noise and joy.

For the first time in a long time, City was asked questions that she could barely find the answers to. Even when Lewis took a free-kick on the edge of Sporting's penalty area, Foden's offer failed to break through the wall. Guardiola was considered powerless in the technical area, while Amorim was considered a coach of cunning and control.

City never wrote themselves off but the conveyor belt of chances had stalled until Silva claimed a penalty when challenged by Ousmane Diomande – with Siebert sent to the touchline by VAR. To his chagrin and despite numerous home whistles, Haaland smashed the penalty onto the crossbar.

It was a long road back from here for the players in blue and a famous final salvo on the Sporting pitch was the prize for Amorim. The decision was sealed when Nunes knocked down Geny Catamo, Sporting's second penalty was taken and Gyökeres converted.

It was City's heaviest defeat since their 5-2 loss to Leicester in 2020 and the best farewell for Amorim.