The 27-year-old, who has lit up social media with his bushy ginger whiskers and picked up two individual bronze medals in Korea, produced a final jump of 136 metres to edge Germany into silver and leave large hill champion Stoch with a team bronze.
"We've been a bit nervous today," said Johansson, his bristly moustache quivering in the chill night air.
"I think it's fantastic to perform like we did," he added, after leading Norway to their first Olympic team gold.
"I did see on the top that we had 22 points on Poland before the last jump. That made me a bit calmer but anyway the nerves are coming more and more as it's closing in to your own jump.
"I just tried to calm myself down to deliver what it took. Nervous, but a fantastic feeling afterwards."
Norway finished with a winning total of 1,098.5 points to Germany's 1,075.7 to snatch top spot in the Olympic gold medal table with 11, one more than the second-placed Germans.
Andre Daniel Tande set the tone for Norway by unleashing a monster jump of 140.5 metres before Andreas Stjernen's effort of 135.5 put their rivals under serious pressure.
Men's ski jump team (L-R) Robert Johansson, Johann André Forfang, Andreas Stjernen and Daniel André Tande. Photo: Terje Pedersen / NTB scanpix
Germany's normal hill gold medallist Andreas Wellinger pulled out a leap of 134.5 metres, which was good enough to earn him a second silver of the Games after finishing behind Stoch in the large hill at the weekend.
Stoch, who did the normal and large hill double in Sochi four years ago, had it all to do on his final jump, but came up short as Poland's men in chocolate brown suits finished third with a total of 1,072.4 points.
"It's still a historic moment for us because it's the first medal for Poland in (team) ski jumping," said Stoch, who tied fellow ski jumper Adam Malysz on a Polish record four Olympic Winter Games medals.
"We did everything that we could. It's a little bit (of a) pity because we were so close to the silver but we're happy."
Germany, meanwhile, won their sixth Olympic ski jumping team medal, a joint record with Austria.
"After the first round we were close to the gold medal but the Norwegian guys were really, really strong today and also the last weeks," said Germany's Karl Geiger.