David McGoldrick fired Sheffield United in front, but Chelsea stormed back to extend their unbeaten streak to 11 games with a an emphatic Premier League win over the Blades at Stamford Bridge.
McGoldrick, who announced his international retirement early this week, conjured up a sharp flick that put the Blades into an early lead, but the Blues hit back for a tenacious turnaround victory.
Chelsea might have lost their five-game clean-sheet streak, with Edouard Mendy conceding his first goal in seven personal appearances but the Blues refused to let the early setback affect their day - in stark contrast to a number of matches last term.
Boss Frank Lampard will be delighted with the Blues' increased steel under duress this term, with his new-look west Londoners growing in confidence by the week.
Chelsea lost at home to West Ham, Bournemouth and Southampton last season, in a campaign where conceding first tended to cost the Blues dearly.
Lampard will hope battling victories like this can consign such brittleness to history, especially if Hakim Ziyech continues to dominate contests as here.
Ajax called Ziyech 'The Wizard of Amsterdam' and his wand-like left foot certainly had the Blades spellbound for much of this clash.
Chelsea have not lost since their 2-0 home reverse to Liverpool on 20 September, and that remains their only defeat in any competition this term.
Striker Timo Werner's return of eight goals in 12 matches and five in his last four adds further momentum to Chelsea's charge, with Lampard's £220million summer overhaul gathering force.
The Blades sneaked into the early lead while Chelsea were still struggling to settle.
N'Golo Kante and Ziyech chased the same man after switching off at a short corner, and that allowed George Baldock to pull a low cutback into the box.
Sander Berge scuffed a shot towards goal that would have proved no threat - but McGoldrick's flick wrong-footed the home defence to put the Blades in front.
And so Chelsea's five-game clean-sheet streak and Mendy's six-game shut-out came to an end, but the Senegal stopper could have no blame attached to him for the concession.
This time last term Lampard's Chelsea would have huffed and puffed and failed to pick apart the resulting low block from a team desperate to defend a surprise lead.
The new-look Blues have far bigger ideas than such inability to blow the house down however, and the ever-dangerous Ziyech kick-started a battling comeback.
The Morocco winger's fine lofted ball turned the defence and sent the underlapping Mateo Kovacic haring down the inside right.
Kovacic then cut back an inviting ball for Tammy Abraham, who swept the ball into the far corner.
Ziyech's teasing free-kick then forced Aaron Ramsdale into an unexpected parry, and Werner was unlucky to see his vicious drive rebound off the crossbar.
Ramsdale's half quickly descended into the immediately-forgettable territory, with the ex-Bournemouth man conceding a needless corner.
Straight from that set-piece Ziyech whipped in a teasing cross - and Ben Chilwell sneaked around the back-post cover to nudge home with his thigh.
Ramsdale ought to have cut out the cross, but even despite that shortcoming, there could be no denying Ziyech's increasing influence on this developing Chelsea team.
Chelsea could easily have added to their lead at the top of the second half, only for Chris Basham to pull off a wonder recovery tackle on Kovacic.
Kante's raking ball had Kovacic clear after Enda Stevens' weak header, but Basham slid in perfectly just as the Croatia midfielder was about to pull the trigger.
First John Egan and then Stevens then denied Abraham at close range as Chelsea continued to push to sew up the win.
But then skipper Thiago Silva flicked home a corner to add the important third, with the Blades frustrated about a foul in the build-up to the set-piece but ultimately outmatched.
Werner clipped a post with a smart lob moments later, but the Germany hitman was not to be denied on the night.
The 24-year-old was quickly set clear again, and doubtless vented some frustrations in lashing past the hapless Ramsdale.