Vonn flew down the course in 1 minute, 38.25 seconds, edging Maze by 0.43 seconds and winning her fifth World Cup event of the Alpine season.
"I risked a lot but could have been a little more clean on the top section," said Vonn. "I skied a really good line on the bottom and was able to carry good speed to the finish."
Vonn said conditions were ideal at Cortina, one of her favorite downhill venues.
"It was a perfect day," she said. "Right away from inspection the sun was shining and the snow was perfect."
Maze, the overall World Cup points leader, said she too enjoyed skiing Cortina and was "really happy with this second place."
American Leanne Smith placed third with a 1:39.14. The United States holds four of the top six places in the downhill standings.