The Slovenian skier finished 0.14 seconds ahead of Nicol Delago, who grew up alongside the Saslong course in northern Italy. Ramona Siebenhofer of Austria came third, 0.51 behind.
Stuhec tore the anterior cruciate ligament in her left knee during a crash while training before last season on the glacier in Pitztal, Austria.
In 2016-17, Stuhec captured the season-long World Cup downhill title. She also won the gold medal at the world championships in St. Moritz, Switzerland, that season.
It’s the first time that the Saslong course is hosting women’s World Cup races, despite being a classic stop on the men’s circuit for a half-century.
The course was shortened for the women and many of the technical sections were left out, including the camel bump jumps.
A super-G race is scheduled for Wednesday on the Saslong.
The races were originally scheduled for Val d’Isere over the weekend but were moved to Val Gardena because of a lack of snow in the French resort.
Overall World Cup leader Mikaela Shiffrin is sitting out the races to rest up for a big block of upcoming technical events — her specialty.
Also missing are Lindsey Vonn and Olympic downhill gold medalist Sofia Goggia, who are out injured until at least January.