Belarus' Yuri Danilochkin placed 33rd, BelTA informs.
The 35-year-old Myhrer finished 0.34 seconds ahead of Switzerland's Ramon Zenhaeusern, who took an unexpected silver medal.
After two falls, Wise got it right at the third time of asking, scoring 97.20 in the final round to push compatriot Alex Ferreira (96.40) into second place. His arch-rival Henrik Kristoffersen of Norway - bronze medalist in Sochi, and second behind Hirscher in the giant slalom here - presents the likeliest threat.
Hirscher, aiming for his third gold medal of PyeongChang 2018, lost control on his first run and failed to complete the course.
Yuri Danilochkin of Belarus placed 33rd, 13.16 seconds behind the victor. The 28-year-old Austrian has won the overall World Cup title in the past six years, and was slalom champion in four of those - feats he is within reach of repeating this season. "But I already had a bad feeling about the whole situation". He followed in the footsteps of legendary Ingemar Stenmark as the only Swedish men to win gold in Alpine skiing.
In other events Thursday, Anna Gasser of Austria won the women's Big Air snowboarding event, and Germany took the Nordic combined team title.
In Gangneung, the US women's team won it all 20 years after their last gold medal in women's hockey and 38 years to the day after the men's famous "Miracle on Ice" victory over the Soviet Union at the 1980 Lake Placid Games.
"The successor to Stenmark in the top honours me, it is one of the greatest athletes in the history of my country". This is what also can happen and is part of the game, part of the sport.
"She made me believe that you can grab the stars and that's what I did today".
"I was standing up there and I knew I had the silver and I only could win and I was like, 'No, I'm going to go full risk and if it works out then I deserve this medal, '" she said.
Wu, who in qualifying broke the previous record set by American John Celski in 2012, went 0.216 seconds faster in the final, with another South Korean, Lim Hyo-jun, taking the bronze medal.
He was assured of a medal when Frenchman Victor Muffat-Jeandet failed to overhaul him, claiming the silver behind Andre Myhrer when Kristoffersen crashed out on his second run.
He is the first Chinese man to win an Olympic short track gold medal and has dominated the distance since Sochi, winning 10 men's 500m races at world championships and in the World Cup.