Ross Barkley sent Chelsea into the FA Cup semi-finals after a deserved 1-0 win at Leicester.
The midfielder came off the bench to keep the Blues' hopes of a ninth FA Cup triumph alive.
Barkley maintained his cup form for Chelsea, having netted in previous rounds against Nottingham Forest and Liverpool.
Leicester lost their first-half threat and their dreams of a maiden FA Cup triumph were ended for another year.
Brendan Rodgers' men, third in the Premier League but just a point above Chelsea, can console themselves with a fight for Champions League qualification, but they will also be looking over their shoulders at in-form Wolves, who are now just three points behind them in fifth.
They are yet to win after the restart and cannot afford to let a promising season end in disappointment.
The Foxes tried to take control early and Harvey Barnes attempted to bulldoze his way through before goalkeeper Willy Caballero palmed away the winger's dangerous low cross.
The bright and industrious Barnes was a focal point in the opening exchanges as the Foxes found space on the flanks to stretch the visitors.
Wilfred Ndidi glanced a header straight at Caballero and the goalkeeper then turned the midfielder's low effort wide after 20 minutes.
Jonny Evans just failed to get a decisive touch on Ben Chilwell's free-kick and the Foxes kept finding pockets of space in the Chelsea back-line.
But they relied on Kasper Schmeichel to keep them level after half an hour when he produced a splendid save to thwart Christian Pulisic.
Leicester were opened up by Mason Mount's cute pass but Schmeichel turned Pulisic's fierce drive over the crossbar.
A minute later Barnes slashed wide and Jamie Vardy scuffed across goal as Leicester finished the first half strongly.
Blues boss Frank Lampard had seen enough and replaced Mount, Reece James and Billy Gilmour with Barkley, Mateo Kovacic and Cesar Azpilicueta at the break.
The switches worked as Chelsea found more rhythm and threat, with Tammy Abraham firing past Schmeichel, although the England striker had already been flagged offside.
Sloppy Leicester struggled to rediscover their momentum with Vardy increasingly isolated, and the visitors made their move after 63 minutes.
The danger had been building and when Willian swapped passes with Azpilicueta he swung in a near-post cross and Barkley arrived ahead of Evans to steer in.
The midfielder, who scored in the previous round's 2-0 win over Liverpool, shot straight at Schmeichel shortly afterwards with Leicester ragged.
Chelsea had seized the advantage and without the ingenuity and vision of James Maddison, out with a knock, the hosts never looked like recovering.
Chilwell drilled at Caballero with 10 minutes left and Caglar Soyuncu's header hit Azpilicueta and bounced over but time ran out for the Foxes.
Schmeichel even denied Chelsea a second in the final minute of normal time when he turned Barkley's drive over.
