Chelsea reached the FA Cup semi-finals as Ross Barkley came off the bench to secure a 1-0 victory at Leicester City on Sunday.
Barkley, one of the three changes manager Frank Lampard made at halftime, slid home the winner in the 63rd minute as Chelsea joined Manchester United and Arsenal in the last four.
"It was important to get the win and keep the momentum going," Barkley said. "At halftime we said it's not good enough and to be vocal on the pitch, and we improved."
Chelsea recovered from a poor start at the King Power Stadium to stay in the hunt for a first trophy of Lampard's reign.
The Blues could easily have fallen behind before the break, but Lampard made the changes at half-time and Barkley – one of the players introduced – clinched the winner.
Chelsea's quarter-final success could be good news as they beat Leicester at the same stage en route to winning the competition for the eighth time in 2018.
Lampard made six changes to the team that handed the Premier League title to Liverpool with a victory over Manchester City on Thursday.
At the start, Chelsea seemed out of sorts and Leicester's Harvey Barnes had a sight of goal inside 30 seconds, the winger's heavy touch letting the ball squirt away as he prepared to shoot.
It was a sluggish start from Chelsea and defender Antonio Rudiger angrily admonished his team-mates after snuffing out a Youri Tielemans raid.
When Wilfred Ndidi was given space to head straight at Willy Caballero, Lampard could be heard shouting "liven up" at his players.
There was no immediate improvement from Chelsea and Billy Gilmour handed possession to Tielemans, who forced Caballero to turn his drive away for a corner.
Leicester defender Jonny Evans headed Ben Chilwell's free-kick wide from close range.
Christian Pulisic had scored in each of Chelsea's first two games since the restart and the winger led their response with an excellent strike that Kasper Schmeichel tipped over.
Lampard still wasn't satisfied and sent on Barkley, Mateo Kovacic and Cesar Azpilicueta at half-time.
Chelsea looked more vibrant after the changes, with Kovacic dominating in midfield. Pressing harder, Chelsea took the lead in the 63rd minute.
Willian swung in a cross from the right and Barkley got in front of Evans to complete a clinical finish past Schmeichel. It was the England midfielder's fourth club goal of the season, with three of those coming in the FA Cup.
There was a worry for Lampard when the in-form Pulisic was forced to come off and needed an ice pack on his leg when he reached the bench. Azpilicueta blocked a goalbound header from Caglar Soyuncu and Ndidi curled wide as Chelsea held on.