Hoefl-Riesch's combined time of 2 minutes, 8.41 seconds was a mere .03 seconds ahead of the American Vonn, who was seeking a sweep of the three World Cup events held at St. Moritz this weekend.
Vonn turned in a faster first super-g leg; however Hoefl-Riesch covered the slalom run in 48.28 to Vonn's 48.54.
"My skiing was good, my concentration was good, but a series of small mistakes cost me much time," Vonn said. "I caught my edges funny a couple of times."
Maze trails Vonn by 387 points in the overall World Cup standings.