The three-time Olympic champion on Saturday posted jumps of 138 metres and 136 metres to finish ahead of Austria's Stefan Kraft and Germany's Karl Geiger.
The victory marked the 34th time Stoch has won a World Cup event.
A day later, the Pole finished ninth in the weekend’s second World Cup competition at Engelberg, or the Hill of Angels.
After seven individual competitions this season, Japan's Ryoyu Kobayashi tops the overall World Cup standings, with 440 points, while Poland’s Stoch is fourth with 275 points.
Polish ski jumpers earlier this month won a team event at the World Cup in Klingenthal, Germany.
Last month, Poland took third place in the World Cup season-opening team competition in their home country, finishing behind winners Austria and runners-up Norway.
The 2019/2020 ski-jumping World Cup circuit features a total of 36 competitions, including six team events, in various countries.
Source: TVP, PAP