James Maddison scored two goals inside the opening 20 minutes at the Etihad
Pedro Porro and sub Brennan Johnson then found the net in the second half
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When all the five-in-a-row talk revolved around Premier League titles nobody doubted Manchester City. When it turned to the possibility of five defeats in a row well, that seemed a little far-fetched.
Four was a new low for Pep Guardiola. But then he signed a new contract and the serenity of his extended presence just as the red half of the city went back to the drawing board seemed as if it would simply soothe away the ills.
Besides, it was Tottenham next. Doctor Tottenham will see you now, as people like to joke but then again, the good doctor does not have the same effect on Guardiola. He has had trouble with them before and there was trouble again.
Not only a fifth defeat in a row, a third in successive Premier League games, but the champions were exposed by Spurs, who were slightly fortunate not to concede but might have scored even more than they did.
James Maddison on his 28th birthday struck twice in the first half and Pedro Porro scored the decisive third, soon after the interval before Brennan Johnson completed the rout in stoppage time, at full stretch to turn in a cross by Timo Werner.
City and their supporters were stunned. And rivals will view this as their chance, a vulnerable point at which they can strike and wrest the Premier League from their grasp. Liverpool will stretch eight points clear if they win at Southampton on Sunday.
Next weekend, Guardiola's wounded champions go to Anfield. They look exhausted. Perhaps at the end of their mental endurance. They are depleted by injuries. Without Rodri, Ruben Dias and more. With Kevin de Bruyne not at his best. And yet so are others. Tottenham came without six, including their first-choice centre halves.
They left not only with the points but with one of their great wins of the Premier League era, cause for celebration for Ange Postecoglou in his 50th Premier League game.
While City had lost their previous four, the first of them at Tottenham in the Carabao Cup, the visitors had been wobbling too, beaten at home by Ipswich on the previous outing. Maddison soon put them in control of this one, however, with two goals in seven first-half minutes.
His inclusion had been a slight surprise because it meant leaving out top scorer Johnson and shifting Dejan Kulusveksi wide when he had been so impressive in a central role.
But Maddison was the only Spurs starter who had not been away on international duty and looked fresh as he drifted in behind John Stones to score the first in the 13th minute, volleying in a teasing cross by Kulusevski, who had escaped Josko Gvardiol far too easily as he gathered a long ball out of defence.
City had started with an intense opening burst. No doubt inspired by positive vibes from Guardiola's contract extension and the elaborate pre-match tribute to Rodri who paraded his Balon D'Or trophy with his name in lights eight feet high across the centre of the pitch, like Elvis Presley had dropped in.
Yves Bissouma collected a yellow card in 12 seconds, a Premier League record. First giving the ball to Phil Foden then hacking him down from behind. It was a reminder of a recklessness he will need to quell with Rodrigo Bentancur banned for seven games.
And a reminder of how just fragile Spurs were at the back when conceding three in the first half at Galatasaray, when Bissouma had the job of shielding the back-up central defenders Radu Dragusin and Ben Davies. The trio were back together but resisted the early pressure. Davies blocked City's first effort of Erling Haaland's efforts and Guglielmo Vicario saved the next with a boot. Once ahead though, the visitors performed with more aggression and surety in their decisions.
Ederson produced a flying save with his fingertips to keep out curler from Heung-min Son destined for top corner before Maddison's second. Again, Gvardiol was at fault. This time guilty of a sloppy pass infield from City's left back area.
It went straight to Maddison, who exchanged passes with Son, picked up the return as he made his way through a congested penalty area and dinked a wonderful finish over Ederson as he dived at his feet.
Unease washed around the Etihad. They are not used to seeing their team so easily exposed and while Guardiola's team continued to create chances going forward, they were unlocked with rare ease as the contest rebounded freely from one end to the other.
Haaland fired over. Ederson denied Dominic Solanke. Vicario saved from Savinho. Bissouma fizzed one over the bar. Each time Spurs sprung on the turnover of possession they were straight at City's centre-halves.
There was no resistance in the area where they have become accustomed to Rodri's presence but there must be more to it than that. Once on top, Spurs looked sharper and hungrier. City, hesitant and unsure.
The next goal felt big, and Tottenham claimed it. Kulusevski carried the ball from inside his own half and overhit a pass for Solanke, who retrieved it, turned and found Porro charging forward from right back. Completely unmarked, he struck it first time, unerringly beyond Ederson.
Belatedly, City found a better rhythm. Haaland struck the bar from a tight angle and Porro deflected wide an effort by Gvardiol. Ederson produced a wonderful save to deny Kulusevski and Vicario kept out an effort from Gundogan before Johnson completed City's misery.
Five in a row, Feyenoord next in the Champions League and then Liverpool.