Oleksandr Zinchenko stepped up to score the decisive penalty to send Carabao Cup holders Manchester City into the semi-finals at the expense of Leicester City.
Kevin De Bruyne gave City the lead on his return to the first team after injury, but Marc Albrighton came off the bench to fire home a deserved equaliser.
With neither side able to find a winner, the game went straight to penalties and, after a series of disastrous penalties, Ukrainian youngster Zinchenko stepped up to fire home.
The Citizens join Burton Albion in the semi-finals after overseeing Middlesbrough at the Riverside in the other tie.
Leicester travel to Chelsea on Saturday before welcoming the champions again on Boxing Day and defeats would heap heat on Puel, with just two wins from his last 10 Premier League games.
He watched on as the Foxes initially offered a listless first-half performance as the visitors dominated and it took just 15 minutes for De Bruyne’s rocket to announce his return.
The midfielder teased Hamza Choudhury on the edge of the area before unleashing a crisp low drive which left the diving Danny Ward with no chance.
The returning Riyad Mahrez hooked over from close range soon after as the Foxes looked likely to roll over.
They had been passive participants prior to the goal, but Demarai Gray did have a 20th-minute effort turned wide by Muric.
It was as good as it got for the Foxes as the visitors looked comfortable without seriously threatening again before the break.
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But within two minutes of the re-start Sergio Aguero forced Ward into a smart low save after De Bruyne had robbed Vicente Iborra.
Maddison was thrown on as Leicester searched for inspiration and the midfielder’s introduction did at least raise the tempo.
But it was Mahrez who nearly added a second when his curling effort from 18-yards whistled inches wide with 23 minutes left.
Leicester’s threat had been slowly growing and they shocked City with the equaliser 17 minutes from time.
Wilfred Ndidi picked out Albrighton with a deep ball which the substitute controlled before rifling an excellent half volley in across Muric.
For the first time the holders were rattled, but they regained enough composure to conjure a chance for Phil Foden but he fired wide.
Choudhury escaped a penalty shout after Gabriel Jesus tumbled before the game had to be settled from the spot.