Chelsea moved into the FA Cup semi-finals as Oliver Norwood's own goal and a late Hakim Ziyech strike capped a 2-0 win against Sheffield United on Sunday.
Thomas Tuchel's much-changed side were far from their best at Stamford Bridge, but Norwood's first-half mistake put them on track to victory.
Ziyech scored in stoppage time as Chelsea sealed their place in the April semi-finals at Wembley where they will take on Premier League champions-elect Manchester City.
The Blues are back in the FA Cup semi-finals for a fourth time in the last five seasons after losing last year's final against Arsenal.
Tuchel's remarkable early impact since replacing the sacked Frank Lampard in January has turned Chelsea in a solid defensive unit.
The German is now unbeaten in 14 games in all competitions, with Chelsea keeping 12 clean sheets in that period, including shutting out the opposition in their last seven matches.
Tuchel made nine changes after Chelsea's Champions League last 16 second leg win against Atletico Madrid on Wednesday.
Kepa Arrizabalaga started in goal, with Billy Gilmour, Olivier Giroud and Emerson among the others to come in.
All the changes left Chelsea struggling to find any rhythm early on. But despite their uncertain start, Chelsea took the lead in fortuitous fashion in the 24th minute.
Aaron Ramsdale couldn't hold Callum Hudson-Odoi's cross and Phil Jagielka scrambled it clear for a corner.
When the corner curled out to Ben Chilwell on the edge of the area, the Chelsea left-back hit a low shot that Norwood turned into his own net as he stretched in a failed attempt to block it.
Norwood almost gifted Chelsea a second goal when his poor pass was pounced on by Christian Pulisic, who raced through on goal but couldn't find the finishing touch as he stumbled before Ramsdale saved his chip.
The Blades are bottom of the Premier League and look destined for relegation following the recent departure of boss Chris Wilder. Pulisic should have put them out of their misery when he jinked past three defenders, only to shoot straight at Ramsdale and scuff the rebound over the bar.
Picked out by John Lundstram's cross, David McGoldrick wasted a golden opportunity to equalise when the United forward sent his diving header wide from just four yards.
Oli McBurnie's long-range drive was pushed away by Kepa before United substitute Rhian Brewster shot just wide.
But United's late flourish wasn't enough to force extra-time as Ziyech came off the bench to fire home from Chilwell's pass.
