It was the second time in three tries that Miller had turned in the quickest time on the downhill course, which was covered by a crust of ice for the closing round of practice.
Although he said he did not plan to go full speed in the training run, Miller wound up .66 of a second faster than Aksel Lund Svindal of Norway.
Miller thus will be the decided favorite when the race is held Sunday.
He is seeking his sixth Winter Olympics medal and his second gold. Miller, however, has yet to win the downhill.
He will be the 13th skier down the course Sunday. American Steven Nyman will go down the mountain first.