The Belgian midfielder had put City ahead with a brilliant 20-yard effort in the 14th minute, his first goal of the season, before Leicester’s Marc Albrighton equalised on the half-volley with around 15 minutes to play.
The game finished 1-1 after 90 minutes - but Muric was the hero when it mattered, saving from James Maddison and Caglar Soyuncu in the shoot-out, before Oleksandr Zinchenko confidently scored the decisive spot kick to send City into the last four.
“He’s [Muric] got veins of ice and did what he had to do, so it’s a beautiful moment for him”, De Bruyne said of the young Swiss.
Muric revealed on how he managed to keep out Maddison and Soyuncu’s efforts, especially the former’s who stuttered in the run-up: “I was waiting for him, so I was looking for the ball… [it was] a great feeling.”
Despite the penalty heroics, it was De Bruyne who put in a man-of-the-match performance on his return to the starting eleven after injury, cutting inside from the left to fire an unstoppable low drive into the Leicester net.
He was understandably delighted to be back in the first team fold: “I’ve been out, so long so to play 70 minutes is a really good sign for me personally.
"I feel a little bit stiff but I’m happy to contribute again.”