Match ends, Chelsea 4, Sheffield United 1.
Chelsea came from behind to beat Sheffield United comfortably at Stamford Bridge, leaving the visitors bottom of the Premier League on another frustrating evening for Chris Wilder's side.
David McGoldrick gave the Blades the lead in the ninth minute with a deft flick from close range.
But Tammy Abraham's scuffed half-volley bounced past Aaron Ramsdale for Chelsea's equaliser, before Ben Chilwell touched in Hakim Ziyech's cross at the back post.
Ziyech turned provider again after the break when Thiago Silva headed in his free-kick at the near post, before Timo Werner added a fourth.
The result leaves Sheffield United with one point from their opening eight matches, while Chelsea move up to third, a point behind leaders Southampton.
- How much trouble are Sheff Utd in this season?
- Reaction from Stamford Bridge and the rest of Saturday's Premier League action
'Amazing' Ziyech impresses
Three of Chelsea's new signings were on the scoresheet but it was another summer recruit who stole the show in west London on Saturday.
Ziyech, who picked up two assists, showed his quality with countless deliveries into the box from set-pieces and a range of exquisite passing.
He was involved in the build-up to the opening goal and his deep cross caused Ramsdale problems minutes later and the ball was parried into the path of Werner, who slid in to smash it on to the crossbar.
Another ball in from Ziyech - almost identical to the previous one - bounced in off Chilwell after Ramsdale failed to deal with it to make it 2-1, and the Moroccan's free-kick was then nodded in by Silva.
The midfielder could have set up a few more too. His sublime ball through to Werner was chipped inches wide by the former RB Leipzig man, who gave a big thumbs up to Ziyech in return.
Manager Frank Lampard was full of praise for Ziyech afterwards, describing the 27-year-old's performance as "amazing".
"He was probably at his best today," Lampard told BBC Sport. "He has a good confidence and arrogance about him - a good arrogance. He will keep trying those passes and keep trying to get those assists."
Sheff Utd's rotten form continues
Sheffield United started the day propping up the Premier League table following Burnley's draw at Brighton on Friday and they will not have a chance to move off the bottom for another 15 days.
It has been a disappointing start for the Blades and any hopes of turning things around at Stamford Bridge seemed to evaporate before half-time.
McGoldrick's delightful flick gave them a surprising lead - it was the first goal Chelsea had conceded in 459 minutes - but it prompted the visitors to drop deeper off the ball rather than play on the front foot.
The Blues took advantage, exploiting their opponents' vulnerability and testing goalkeeper Ramsdale with constant deliveries into the box.
Ramsdale himself had a few nervous moments - the hesitation for Chilwell's goal, the parry which was almost rebounded in by Werner and a fumble from Ziyech's cross in the second half.
Sheffield United, who were able to keep the scoreline down against Manchester City on 31 October, could not do the same at Stamford Bridge and they provided very little threat going forward.
The international break potentially comes at a good time for the Blades, after defeats by Liverpool and Arsenal, as well as City and Chelsea, in the past month.
It will be a crucial period when they return too, as they take on 15th-placed West Ham United and West Bromwich Albion, who are third from bottom before they host Tottenham on Sunday.
'The balance of the team felt great' - what they said
Chelsea manager Lampard to BBC Sport: "It was enjoyable. This is a team that is so difficult to play against. They are a great team with an incredible coach. The reaction was brilliant to the goal - we created a lot and were really secure. I'm happy with everybody.
"The balance of the team felt great. There were so many good things in what we were creating, we scored two goals from set-pieces.
"I don't want to get too carried away but I'm happy."
Sheffield United boss Wilder to BBC Sport: "At times my teams are naive. It's irrelevant. We have given away some poor goals. I think we have to look at ourselves.
"If you give handouts to world-class players they will take their opportunities - which they did. It's no good opening up then as it could be any score."
The best of the stats
- Chelsea have lost just one of their past six Premier League games against Sheffield United (W4 D1), but this was their first victory over the Blades in the competition since March 2007.
- Sheffield United's return of one point from their opening eight league games this season is the joint-lowest points tally at this stage of a Premier League campaign, alongside Manchester City in 1995-96 (relegated), Southampton in 1998-99 (avoided relegation), Sheffield Wednesday in 1999-00 (relegated) and Sunderland in 2013-14 (avoided relegation).
- Chelsea's 11 matches without defeat is their longest unbeaten run since November 2018 (a run of 18), while Sheffield United's 12-game winless run is the longest they have gone without a victory since October 2013 (a run of 13).
- McGoldrick's opener was just the second goal Edouard Mendy has conceded for Chelsea and the first since the keeper's debut against Tottenham in September. He had kept six consecutive clean sheets before Saturday.
- Defender Silva became the sixth-oldest player to score for Chelsea in the Premier League (36 years 46 days) and only Glenn Hoddle (36 years 150 days) got his first goal in the competition for the Blues at an older age than the Brazilian.
- After failing to score or assist a goal in his first four Premier League appearances for Chelsea, Werner has been involved in five goals in his past four (four goals, one assist).
Sheffield United host West Ham in the Premier League on Sunday, 22 November (14:00 GMT), while Chelsea travel to Newcastle the day before (12:30).
- 6Thiago Silva
- 17KovacicSubstituted forJorginhoat 71'minutes
- 11WernerSubstituted forGiroudat 87'minutes
- 12EganBooked at 37mins
- 8BergeBooked at 75mins
- 16NorwoodSubstituted forOsbornat 62'minutes
- 24BrewsterSubstituted forMcBurnieat 63'minutes
- Jonathan Moss
- Shots on Target
Second Half ends, Chelsea 4, Sheffield United 1.
Corner, Chelsea. Conceded by Aaron Ramsdale.
Attempt saved. Mason Mount (Chelsea) right footed shot from outside the box is saved in the top centre of the goal. Assisted by Ben Chilwell.
Corner, Sheffield United. Conceded by Thiago Silva.
Attempt blocked. George Baldock (Sheffield United) right footed shot from outside the box is blocked. Assisted by Ben Osborn.
Corner, Sheffield United. Conceded by Tammy Abraham.
Substitution, Chelsea. Olivier Giroud replaces Timo Werner.
Corner, Sheffield United. Conceded by Reece James.
Thiago Silva (Chelsea) wins a free kick in the defensive half.
Foul by Oliver McBurnie (Sheffield United).
Foul by Hakim Ziyech (Chelsea).
Sander Berge (Sheffield United) wins a free kick in the defensive half.
Goal! Chelsea 4, Sheffield United 1. Timo Werner (Chelsea) right footed shot from the centre of the box to the centre of the goal. Assisted by N'Golo Kanté.
Ben Chilwell (Chelsea) wins a free kick in the defensive half.
Foul by Oliver McBurnie (Sheffield United).
Timo Werner (Chelsea) hits the right post with a right footed shot from outside the box. Assisted by Hakim Ziyech with a through ball following a fast break.
Goal! Chelsea 3, Sheffield United 1. Thiago Silva (Chelsea) header from very close range to the bottom left corner. Assisted by Hakim Ziyech with a cross following a set piece situation.
Reece James (Chelsea) wins a free kick on the right wing.
Foul by Max Lowe (Sheffield United).
- Watch 13 first-round ties on BBC iPlayer and the BBC Sport website and app this weekend. Find out more here.