Andrighetto's marker held until the third round of the skills competition when Ekman-Larsson beat Swiss netminder Leonardo Genoni with a clean wrist shot. Forsberg gave the Swedes their first lead of the night in the fourth round of the shootout before Nilsson denied Nino Niederreiter's (Minnesota Wild) ensuing shot to erupt a celebration on his bench and with the pro-Sweden crowd that made the quick trip across the Oresund Strait.
Switzerland took leads of 1-0 in the first period and 2-1 in the second, but Sweden answered each time before the intermission. Tre Kronor ended with 32-18 edge in shots on goal through regulation, but overtime was more even.
The two countries traded opportunities in the 20-minute, 4-on-4 OT, which saw Switzerland outshoot Sweden 9-5 in the session. The Swiss had some chances in the low slot, while the Swedes hit a few posts--including one in the final seconds.
Genoni stopped 35 shots for Switzerland, one day after he made 43 saves in a 3-2 victory over Canada in the semifinals.
Watch: Sweden-Switzerland Gold Medal Game Recap
Andrighetto was busy in overtime, as he played 5:21 of his 19:48 of ice time in the extra session. Officially, he closed the game with one shot on goal, a minus-1 rating and a 50-percent success rate on faceoffs (2-for-4) while skating on a top-six line with Timo Meier (San Jose Sharks) and Joel Vermin.
The Zurich native finished the tournament tied for first on Team Switzerland in scoring with nine points, tallying two goals and adding seven assists in nine games. His 21 shots on goal were tied for the third most on the club.
The silver is Andrighetto's first medal of any kind in international competition and the third, second-place finish for Switzerland at the World Championship. The Swiss' only other medal in the last 65 years at Worlds was a silver they earned in 2013; they lost 5-1 to Sweden in the final.
Andrighetto was playing in his second World Championship after participating in seven games at the 2016 tournament. He had previously represented his country at the 2010 and 2011 IIHF U18 World Championships and the 2012 and 2013 IIHF World Junior Championships.