Thomas Tuchel named a much-changed squad for Chelsea's final game before the international break. Starts were handed to the likes of Ben Chilwell, Kepa Arrizabalaga and Billy Gilmour, although the ever-present Mason Mount was handed the captain's band.
The visitors went against the form book and started the game on the front foot, as Chelsea struggled to get going in the game's early exchanges. However, Sheffield United failed to make the most of their early dominance, and it was somewhat inevitable that Chelsea would make them pay.
A corner kick was not dealt well by Sheffield as Ben Chilwell's shot/cross was unfortunately deflected past his own goalkeeper by Oliver Norwood.
The goal injected some life into the hosts, but their decision-making in the final third left a lot to be desired, with Thomas Tuchel showing his displeasure with overhit passes on several occasions.
Norwood's day almost went from bad to worse after an under-hit backpass was pounced on by Christian Pulisic. But the American's shot at goal in the 45th minute was well saved by Aaron Ramsdale, who rushed out to narrow the angle.
Remarkably, that was Chelsea's first and only shot on target in what was a largely underwhelming first-half display.
The second half started in much the same way as did the first. The Blades asked all the questions as Chelsea's sloppiness in possession kept Sheffield in the game. The visitors had two good chances in quick succession to draw level but squandered both opportunities.
A pin-point delivery by John Lundstram found an unmarked David McGoldrick in the box, but he sent his wayward header wastefully wide with only the Chelsea goalkeeper to beat.
A minute later, Oliver McBurnie forced Kepa Arrizabalaga into a smart save with a well-struck shot from 25 yards. At this point, it looked increasingly likely that Sheffield were going to grab an equaliser.
Another great chance came the way of the visitors in the first minute of injury time when a rebounded ball fell into the path of Rhian Brewster. The former Liverpool man, however, flashed his shot wide when he should have done much better.
Chelsea punished the visitors for their profligacy when substitute Hakim Ziyech showed great technique to score his side's second. After Ben Chilwell sent a lofted ball into the box, the Morocco international controlled excellently before rifling a low shot beyond Ramsdale and confirm Chelsea's win.
The victory saw Chelsea book reach a fourth FA Cup semifinal in five seasons. On that note, let's take a look at five talking points from the game.
#1 Impressive Sheffield United deserved better
Sheffield United are on their way to the Championship after what has been a disastrous Premier League campaign.
However, their spot in the league table is not an accurate reflection of their performances. Despite ending on the losing side against Chelsea, the Blades more than gave a good impression of themselves.
They registered more shots on target than their hosts and had several good opportunities to get on the scoresheet.
Throughout this season, the South Yorkshire club have been plagued by poor finishing, and the same problem came to the fore once again against Chelsea.
For most of the game, Chelsea hung on for dear life while Sheffield United asked all the questions, so their 2-0 victory was a flattering scoreline of sorts.
#2 Chelsea record yet another clean sheet under Tuchel
Chelsea have been marked by a new-found defensive solidity since the appointment of Thomas Tuchel. Despite gifting several chances to Sheffield United, the Blues managed another shutout.
This latest clean sheet means the Stamford Bridge outfit have kept 11 shutouts in 14 matches under Thomas Tuchel, conceding a meagre three goals in this period.
Moreover, Chelsea are yet to concede in seven home games under the German tactician. Despite not playing free-flowing football, this new-found defensive solidity could be the bedrock for Chelsea's success this term.