Norwegian Marit Bjorgen's silver medal in the same event saw her become the most decorated female Winter Olympian of all time.
There were also gold medals for German biathlete Laura Dahlmeier(women's 7.5km sprint), German ski jumper Andreas Wellinger (men's normal hill) and Dutch speed skater Carlijn Achereekte, who led home team-mates Ireen Wust and Antoinette de Jong in the women's 3,000m.
The unified team was formed after the two Koreas reached a deal to compete under the same flag at the Games, and at Friday's opening ceremony athletes from both nations marched together into the arena.
Under the arrangement, 12 North Korean players were added to the South's full roster of 23 players and three players from the North were on the ice at any time.
The team were watched by dignitaries including International Olympic Committee president Thomas Bach, South Korean president Moon Jae-in and Kim Yo Jong, the sister of North Korean leader Kim Jong Un.
Their build-up to the Games was less than smooth - their only practice match resulted in a 3-1 defeat by Sweden and the language barrier also required coach Sarah Murray to have her commands translated from English into Korean and then into North Korean so those players could understand.
Although they received a rapturous welcome at the Kwandong Hockey Centre, including from the North Korean cheerleaders, the team - who are the eighth seeds in the competition - found it tough on the ice.
Alina Muller scored a hat-trick in the first period and added another in the second before Phoebe Stanz and Lara Stalder scored two apiece as the Swiss managed 52 efforts on target to their opponents' eight.
There was a carnival atmosphere as the near-capacity crowd cheered for the home team from the moment the puck dropped, roared each time a Korean player held possession with many waving unification flags.
Some 100 North Korean cheerleaders were on hand, decked out in red track suits, leading chants for the spectators and singing North Korean pop songs.
"I feel really good and touched. I feel fortunate to see a historic game. This will contribute to inter-Korean peace," said Jang Sung-ho, who came to watch the games with seven other family members.
"It is a historic game. This small step will pave the way for inter-Korean peace," said office worker Oh Eun Seok.
Bjorgen satisfied with silver
Bjorgen's silver in the skiathlon - an event in which competitors ski 7.5km in freestyle before 7.5km in skating style - saw her overall medal tally rise to 11 and she overtakes now-retired cross country skiers Russia's Raisa Smetanina and Stefania Belmondo of Italy.
Her compatriot, biathlete Ole Einar Bjorndalen has the overall record with 13 medals, which the 37-year-old could surpass in Pyeongchang, but she said she was not disappointed with silver.
"This season wasn't that good for me - it has been up and down," she said. "To be fighting for a medal in the Olympics, it's not that easy.
"I have been very good for many years, but I'm also getting older and the younger girls are getting better. I don't think I'm going to come and take gold so I'm happy with silver
"It's my last Olympics, but I have to focus on doing a good race. When I'm finished I can look behind me and see how many medals I have. For now, it's important to focus on the races."
Home pressure for Lim
Lim's victory in the 1500m short-track speed skating event gave South Korea their 22nd gold medal in the sport since it made its debut in 1992.
And the 21-year-old admitted to being under pressure going into Saturday's racing.
"I was very overwhelmed because it's my home country," he said afterwards. "All my family is here to cheer me on.
"I wanted to show my really good attitude and best efforts, but the coach said, 'Don't stress yourself too hard. Make yourself comfortable'.
"I just followed his direction and I think that led to better results."
Other news headlines on day one
The South Korean government has launched an investigation into a possible cyber attack during the opening ceremony. What organisers describe as non-critical parts of the internal systems went down 45 minutes before the ceremony began, affecting the phone and internet services, but it did not affect the ceremony.
Cases of norovirus have risen to 139 but organisers claim the outbreak is under control.
Figure skater Yuna Kim, who lit the Olympic cauldron, said it was an "unforgettable experience". She revealed she had been nervous because there had only been one rehearsal and she was worried about falling over.
The spectacular sight of 1,218 drones forming the Olympic rings during the opening ceremony was pre-recorded.