Austria's Christoph Gruber was fastest in on the full-length men's course with a 2:10.82. Bode Miller of the United States had the 13th fastest time.
Vonn sailed down the partial-course training run at Val d'Isere in 1:18.65, 0.38 of a second faster than her young French rival, Marie Marchand-Arvier.
"I have a good feeling on my skis," said Vonn, who edged the 23-year-old Marchand-Arvier in the super G world championship. "I'm relaxed and just trying to execute the line. Today was just a training run and tomorrow there will be a lot more attack."
Vonn leads in the World Cup overall standings for this season and in the downhill. Marchand-Arvier is 23rd overall while Germany's Maria Riesch is second in the overall point total.