Chelsea substitutes Carney Chukwuemeka and Noni Madueke scored stoppage time goals to earn a thrilling 4-2 home victory over battling second-tier side Leicester City on Sunday and a place in the FA Cup semi-finals.
The match had everything needed for a classic cup tie, including end-to-end action, a missed penalty, a red card, a howler of an own goal and some sumptuous strikes.
Chelsea had looked in full control at halftime after goals from Marc Cucurella and Cole Palmer, though Raheem Sterling also had a somewhat feeble penalty saved by Jakub Stolarczyk's legs.
However, a horrible mistake from Chelsea's France defender Axel Disasi gifted Leicester a goal in the 51st minute when his pass back from distance flew straight into his own goal.
Ten minutes later Stephy Malvididi produced a stunning individual goal, dribbling and sidestepping Malo Gusto before curling the ball into the top corner to put Leicester level.
In the 71st, Leicester's Callum Doyle clipped Nicolas Jackson's heel as the striker raced towards goal.
Referee Andy Madley signalled a penalty and a yellow card but after a VAR check he ruled that the foul had happened just outside the penalty area and changed the yellow to a red because Jackson had been clear on goal.
Chelsea besieged the Leicester area, producing a total of 26 shots to the Championship side's five, but they also missed a hatful of chances and were guilty of many misplaced passes.
Chelsea coach Mauricio Pochettino, who has suffered criticism for some of his side’s performances in the league this season, said the game had been tougher than it needed to be.
“Because if we score in the first half all the chances we create, it is finished in 45 minutes," he said.
He added that fans who have booed Chelsea off the pitch in some recent games should trust him.
"Fans are entitled to show their emotion. For us we try to emphasise with our fans not to criticise. They want the best for our team and players. But we are in a project. We need support and to really believe. We are trying to build something."
He said he would support Sterling who was booed off when substituted after missing a couple of big chances as well as the penalty.
“The feelings weren't good for him but I am going to support him. He has an unbelievable CV. Playing for big teams, an experienced player."
But it was Pochettino's late substitutes who turned the match round.
With eight minutes added on, Chukwuemeka turned Cole's expert back flick into the net and Madueke looped home a brilliant shot from distance to make it four just before the final whistle.
Chelsea, who lost the League Cup final to Liverpool last month, will be at Wembley again next month for their sixth FA Cup semi-final in eight years.
They will meet either Coventry City, Manchester City or the winners of Sunday's late quarter-final tie between Manchester United and Liverpool.
Leicester, who have led the Championship for several months, return to their pursuit of promotion to the Premier League.
Manager Enzo Maresca said their main target was the league. "We don't like to lose games but the effort and performance was very good. We scored twice but then the red card completely changed the dynamic."