The Sochi 2014 Olympian combined to finish the two runs in 1:43.09 to claim the final spot on the podium as local Dusan Sencar took the victory.
Demschar had little time to rest and celebrate his medal as he headed to Seefeld in Austria for two Slalom events on Saturday where he claimed 12th and then did not finish the first run of the final event.
Demschar’s Sochi teammate and fellow PyeongChang 2018 hopeful Greta Small was also in action, albeit against much tougher fields at the Cortina d’Ampezzo World Cup.
Small lined up against the world’s best as she competed in two Downhill competitions at the site of the 1956 Olympic Games.
She claimed 36th in a time of 1:42.17 in the first event, as Italy’s Sofia Goggia took the win in a time of 1:36.45.
In the second event she finished in a time of 1:43.31 in 47th as Lindsey Vonn took the win in 1:36.48.
Both Small and Demschar are aiming to be selected for their second Olympic appearances at PyeongChang 2018.
In Sochi Small competed in all five events as an 18-year-old, claiming her best result with a 15th in the Super G.
Demschar lined up in two events in his Olympic debut, finishing 39th in the Giant Slalom before getting a DNF in the Slalom after not completing his second run.