An 18-time winner at Lake Louise, Vonn was able to get up after the wreck in "Claire's Corner" and ski to the bottom of the course. She was the fastest at each of the four intermediate stages and had a 0.05-second lead when she wiped out.
Vonn did not speak to media and declined autograph-seekers, saying: "I have to go ice my hip."
She later tweeted: "Well that hurt... had a nice lead the whole down but caught my inside ski. I'll be sore tomorrow but will rest up tonight and barring anything major I will be racing. Can't keep me down!"
Vonn is back at the resort west of Calgary after missing the stop last season because of a broken arm. The 33-year-old American star has a record 77 career women's World Cup victories. She is a four-time overall World Cup champion and won the 2010 Olympic women's downhill.
Huetter returned from a knee injury that sidelined her since January to race to her first downhill victory and second overall World Cup win. In steady snow, she finished in 1 minute, 48.53 seconds.
"It's unbelievable," Huetter said. "It's my first race after the injury, so it's my comeback and it's the best comeback I've ever dreamed about."
Tina Weirather of Liechtenstein was second in 1:48.62. She slipped coming out of the final turn.
"That cost me the win," she said. "That's a pity because I was really close."
American Mikaela Shiffrin was third in 1:48.83, the first podium in three career downhills for Shiffrin - the World Cup overall and slalom champion last year and defending Olympic slalom champion.
"I'm still not sure what my expectations are in downhill and today was an amazing day," Shiffrin said. "I've definitely made a lot of progress in my downhill. Super-G comes a little bit more naturally because there's a little bit more turning. Downhill, I'm always surprised at how much time there is to make the turns. That's something I've worked on a lot, being a little more patient."
American Jackie Wiles was fifth for her second career World Cup top-five finish.
A second downhill is scheduled for Saturday, followed by a super-G on Sunday.
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