So Thomas Tuchel is not perfect after all.
And having spent the past six months or so inside Pep Guardiola’s head, he can consider himself evicted for now.
Instead, the German will be left to pore over his own role in this first defeat of the season for Chelsea that saw them miss the chance to open up a six-point gap on Premier League champions Manchester City.
He got his team selection all wrong, waited too long to make the necessary adjustments and in the end he could consider himself fortunate to lose to just the solitary goal from Gabriel Jesus.
It was Guardiola who was accused of over-thinking last season’s Champions League final, naming a starting XI that included neither a holding midfielder nor a striker.
But on this occasion, it was Tuchel who offered up a confusing lineup, with N’Golo Kante as his most creative midfielder. As a result the France international neither provided the guile as a link man, nor the ball-winning qualities that are his hallmark. On too many occasions he was bypassed in an opening period in which City dominated.
It left Chelsea with Romelu Lukaku and Timo Werner stranded up the pitch, their teammates struggling to find them in the face of the visitors’ press.
With Mason Mount injured, Tuchel had opted against starting Kai Havertz and how he missed the German’s ability to hold the ball up and run at players.
Too often Lukaku and Werner lacked the touch and link-up to punish City as Ruben Dias and Aymeric Laporte bossed the Chelsea forwards.
In Tuchel’s defence, he could point to an early injury to Reece James as a reason for not making what is becoming a customary half-time change. But with the game goalless at the break he missed the opportunity to make a decisive intervention.
It was not as if he did not know the game was going against him. He cut an agitated figure throughout the first half – and as the game drew to a close, he was apoplectic with each decision that went against his side.
Yet he could not complain about the result. City were deserved winners and but for heroics from Edouard Mendy and a goal-line clearance from Thiago Silva, they would have left Stamford Bridge with a much more handsome margin of victory.
Of even more annoyance to Tuchel will be the fact that the decisive goal – eight minutes after the break – was the type which Chelsea do not concede.
They were too slow to react to a short corner, too slow to close down Joao Cancelo on the edge of the box as he got a shot away. And despite having all three centre backs on Jesus, they allowed the Brazilian to control the ball with his back to goal, turn and shoot, his shot taking a deflection on its way into the corner of the net.
Only then did Tuchel make the necessary adjustment with Havertz coming on for Kante on the hour-mark. There was still time to salvage something and the man who scored the winning goal in the Champions League final had an immediate effect, laying off to Lukaku to put the ball in the back of the net.
It was ruled out for offside, but in one moment, he demonstrated what Chelsea had lacked over the previous hour.
While Tuchel got it all wrong, Guardiola called it perfectly.
With Phil Foden as a false nine, he dominated midfield. Kante’s influence was virtually nullified, Jorginho could not get the ball out of Chelsea’s half quickly enough and it was only the running of Mateo Kovacic that relieved the pressure on the home side, even if his final ball let him down too often.
In contrast the movement and quick passing of Bernardo Silva, Kevin de Bruyne and Rodri saw City take total control.
But that is often to be expected and Tuchel’s success against Guardiola – beating him on three occasions last season – has come in his ability to counter quickly and ruthlessly exploit City on the break.
The potential to do that again was still clear and Chelsea were close to making Guardiola pay again in the first half.
Marcos Alonso’s quick through-ball to Werner gave the forward chance to run Ruben Dias. His touch took him too wide to get a shot on goal, but he was alert enough to cross to Lukaku, who looked set to open the scoring before Cancelo’s intervention.
It would be the only real chance Chelsea would have – and with it went any chance of getting anything out of the game.