Fenninger finished in 1 minute, 10.29 seconds. Tina Maze of Slovenia was second, 0.03 seconds behind, and Lindsey Vonn third despite a wind gust standing her up early in her run.
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Fenninger was the super-G winner at the Sochi Olympics.
Vonn, the favorite in a race so close to her hometown, momentarily had the lead and the capacity crowd went wild. Her boyfriend, golfer Tiger Woods, yelled "Yes," after seeing the time on the board.
It didn't last. Maze was the next skier down and took the lead.