The German extended his unbeaten run in all competitions to 11 with last night's win against Everton to strengthen his push for Champions League qualification. But the club's remarkable resurgence under him is also serving notice of a title challenge next season that should have Manchester City and Guardiola looking nervously over their shoulders.
Tuchel's first four months in the job were always going to be about more than just securing the minimum target of a top-four finish: they were an audition for Roman Abramovich; a chance to prove the German could go head-to-head with Guardiola and Jurgen Klopp in the battle for supremacy.
Imagine, for instance, if a run of games against Atletico Madrid, Manchester United, Liverpool and Everton had not ended with three wins and draw; if Chelsea were battling to overturn a first-leg deficit in the Champions League, had lost ground on second-placed United and were overtaken by both Merseyside clubs.
With just an 18-month contract at Stamford Bridge, would Tuchel get the chance to embark on a full season if he failed to secure top four? Particularly with options such as Julian Negelsmann potentially being available in the summer?
He should not have to find out the answer to that after turning Chelsea into a near-impenetrable force and overseeing a run that justifies
Abramovich's belief that Frank Lampard was failing to realise the true potential of a hugely talented squad, assembled at great expense.
It is a measure of the work carried out by Tuchel in such a short space of time that their form is so closely aligned to this record-breaking City team.
Considering two points were dropped in his first game in charge — the goalless draw with Wolves just 24 hours after his appointment — the margin between the sides might be shorter still. And Tuchel is still kicking himself for the 1-1 draw away to Southampton last month and his own contribution to that result.
He is proving himself to be a perfectionist, with Chelsea's record of nine clean sheets in 11 games representing an obsessive commitment to keeping opponents at bay.
Not that he has turned Chelsea into a negative team — rather, the levels of control they demonstrate have suffocated the life out of their rivals.
Their meeting with City on May 8 will make for engrossing viewing given Guardiola's own insistence on dominating possession. It will also serve as a fascinating gauge ahead of next season and what could be the top-flight's next great rivalry.
Tuchel is already laying down a marker — and the anticipation is that this team will only improve. After transforming his defence, he continues to tinker with his attack.
Erling Haaland may well be added to an already rich array of talent up front, but Tuchel is determined to find the most effective balance of his existing options to see out this season.
Deploying Kai Havertz as a false No9 could well be key to that, with German outstanding last night.
His first-half attempt on goal took a deflection off Ben Godfrey to put Chelsea ahead and he went on to win the penalty that saw Jorginho complete the scoring from the penalty spot after the break.
Timo Werner, though, continues to be fitful, but these things take time, particularly when a manager has been parachuted in midway through the season.
Which only goes to make Tuchel's impact all the more impressive — and a warning to their rivals next term.