Roared on by the home crowd on the start of a lunar new year observed in Korea, the 23-year-old stormed to his country's second gold medal of the Games -- with plenty to spare.
Yun clocked a combined time of three minutes, 20.55 seconds for his four runs, with Nikita Tregubov, an Olympic Athlete From Russia, taking silver.
Dom Parson's celebrated with gusto after winning Britain's first skeleton medal in 70 years. But the day belonged to Yun, who slides in an Iron Man-copy helmet that makes him look like a superhero as he rockets around the course.
"It has been my dream to win the gold medal since I started off in skeleton," the South Korean told reporters after winning by a record margin of 1.63 seconds.
"But this is just the beginning for me."
Yun sank to his knees as he soaked up the adulation of the crowd, thanking them for their raucous support as they chanted: "Yun Sung-bin, Yun Sung-bin!"
"I was a little worried about racing on the morning of the lunar new year," added the former world silver medallist.
"It's a national holiday so I thought not many people would come to support. But so many people came to watch and I know many more watched on TV. That support really helped push me to win the gold medal."
Before these Games, only nine different countries had won medals in skeleton, where athletes throw themselves down an icy shute on the bellies head-first.
Typically the likes of the United States, Austria, Canada, Germany and Switzerland have dominated the sport but Yun upset the established order with his breath-taking speed.
"It feels unbelievable to win Olympic gold," said Yun. "It's a great honour."
Parsons, who finished just two hundredths off silver, was nevertheless ecstatic after claiming Britain's first medal of the Games.
"I don't know, it hasn't really sunk in yet -- I thought I'd lost it after that fourth run," he said after a mistake from Latvia's Tomass Dukurs allowed him to slip into medal contention.
"I was very lucky to be able to move up. Martins is the last person I'd expect to make those kind of mistakes. He's been dominant for so many years.
"It's incredible, four years of work has gone into this."