Hanyu lost his balance twice in his free skate but a total score of 317.85 gave the peerless Japanese gold with room to spare over compatriot Shoma Uno and Spain's Javier Fernandez.
America's Nathan Chen had earlier become the first skater to land six quads in competition but despite his Olympic free-skate record of 215.08, it was only enough for fifth.
Hanyu, greeted by a shower of Winnie the Pooh stuffed toys, his mascot, air-kissed Uno and theatrically leapt onto the podium at the award ceremony.
Hanyu was back on the ice competitively for the first time since injuring his right ankle last November.
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"My right foot really hung tough,"
he said.
"I was so fortunate. I'm feeling gratitude. I was able to make a jump that I wanted to do with concentration. Anyway it was good."
Meanwhile Ledecka of the Czech Republic pulled off one of the biggest surprises ever seen at the Games when she won the super-G, as American star Lindsey Vonn finished sixth.
Not only did Ledecka deprive Veith of what looked like a rare double, she pushed Vonn back into sixth spot, the American star paying the price for a massive error that saw her lose valuable time at the bottom of the course.
'Definitely shocking'-
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Ledecka was stunned and open-mouthed with disbelief.
"All the other girls didn't risk a lot. There must be a lot of pressure on them. I was just trying to do my best run," she said.
Vonn said the outcome was "definitely shocking."
"She beat me in training in Lake Louise -- that was also surprising."
"I feel like in the Olympics a lot of things can happen, it's not that she didn't deserve it, but there's a lot of pressure on the favourites."
Jamaica's women made their bobsleigh debut in their original sled, despite the donation of a new model from a beer company following a dispute with their former coach.
The teams that brought us the 1980's "Miracle on Ice" are now meeting in the group stage, and after the NHL opted against releasing its players for the Games.
The Russians are also competing as neutrals after their national Olympic committee was banned over a systemic doping scandal.
South Korea's Choi Min-jeong, 19, gets a second chance for gold in the women's 1,500m after she missed silver following a disqualification in the 500m.
And Poland's Kamil Stoch, double Olympic champion four years ago, lines up to defend his men's large hill title after finishing a disappointing fourth in the normal hill.