The two Koreas marched together and South Korea's president shared a historic handshake with Kim Jong Un's sister as the Pyeongchang Winter Olympics opened in a spirit of intense rapprochement on Friday.
At a glittering but sub-zero ceremony, South and North Korea brought the crowd to its feet as they entered behind the blue-and-white Korean unification flag.
South Korean President Moon Jae-in shook the hand of a smiling Kim Yo Jong, the powerful sister of North Korean leader Kim Jong Un, as he entered the VIP seating section, and again as the Korean athletes marched.
It cemented what has been a rapid improvement in Korean ties since North Korea -- after months of fierce nuclear rhetoric and missile tests -- agreed last month to attend its first Olympics in the South.
Kim Yo Jong, the first member of the North's ruling dynasty to venture South since the Korean War, forms part of the highest level delegation ever to cross the border.
South and North Korea last marched together at the 2006 Winter Olympics in Turin. They also made the symbolic gesture at the opening of the 2000 and 2004 Olympics in Sydney and Athens.
"You will inspire us all to live together in peace and harmony despite all the differences we have," said International Olympic Committee president Thomas Bach, before Moon declared the Games open.
"You will inspire us by competing for the highest honour in the Olympic spirit of excellence, respect and fair play," said Bach.
"You can only enjoy your Olympic performance if you respect the rules and stay clean."
UN Secretary-General Antonio Guterres urged North Korea's ceremonial head of state Kim Yong Nam to engage in dialogue on ending the nuclear crisis during a brief exchange in South Korea, a UN spokesman said.
Kim and Guterres attended a dinner ahead of the opening of the Olympics.
"He did have a brief exchange with president Kim," said UN spokesman Farhan Haq.
Guterres reiterated "his expectation and hope that all parties will use dialogue to achieve the peaceful denuclearization of the Korean peninsula," he added.
Russia's athletes entered Friday's ceremony behind a neutral flag after their team was suspended over a doping scandal. Despite the ban 168 "Olympic Athletes from Russia" will compete in Pyeongchang.
Just hours earlier, 47 Russians lost a court bid to take part in the Games after they were left off the list of athletes deemed clean from doping.
- Oiled Tongan -
Shivering athletes are bracing for one of the coldest Winter Olympics on record, with real-feel temperatures plumbing minus 10C at the opening ceremony.
Japan's speed skaters were among the athletes who decided it was just too cold to brave the open-air ceremony, while organisers handed out heat packs, blankets and hats to keep spectators warm.
But Tonga's Pita Taufatofua, echoing his eye-catching entrance at the Rio Olympics, happily braved the chill as he appeared stripped to the waist and with his chest heavily oiled.
Expectations are sky-high for an array of stars at Pyeongchang, including American skiers Mikaela Shiffrin and Lindsey Vonn, while the drama in figure skating centres on whether Japan's "Ice Prince" Yuzuru Hanyu can recover from injury to retain his crown.
Potential winners also include French flag-bearer Martin Fourcade in biathlon, hoping to add to his two gold medals in Sochi in 2014.
Alpine giant slalom great Marcel Hirscher of Austria is also among the gold medal hunters.
The sensational 15-year-old Alina Zagitova of Russia will take the spotlight in women's figure skating, where a showdown is expected with her fellow Russian teen, Evgenia Medvedeva.
Another teenage breakout star could be Chloe Kim, 17, the American whose parents are Korean and who is tipped for gold in snowboard as well as adulation by the host nation.
For the South Koreans, major home hopes rest on the slender shoulders of yet another teenage girl.
In short-track speed skating, the 19-year-old Choi Min-jeong is among the favourites for a gold-medal sweep of all four races.