Fenninger won the opening giant slalom in Are on Thursday, fighting back from seventh after run one, and repeated the trick 24 hours later, although no comeback was needed this time.
The 24-year-old, who won giant slalom silver at last month's Winter Olympics as well as the Super-G title, led after a posting a first run time of 58.49 seconds in Sweden.
And Austrian Fenninger was not to be denied a second win in as many days with her time of 1:01.66 minutes from her second run giving her a winning margin of 0.61.
Viktoria Rebensburg placed second while Jessica Lindell-Vikarby gave the Swedish home crowd something to shout about as she placed third a further 0.07 behind.
Fenninger's win saw her overtake Maria Hoefl-Riesch in the overall World Cup standings by seven points and close the gap on Lindell-Vikarby in the giant slalom standings by 14.
Hoefl-Riesch was tenth in Are after a 21st in the first race on Thursday with five races left overall this season and the giant slalom Crystal Globe the last individual title to be decided.
- Sports & Recreation
- giant slalom