"I got a little bit too inside and lost my outside ski," Vonn said. "My knee came up and hit my chin."
U.S. Ski Team spokesman Doug Haney said Vonn banged her finger a little bit, but was otherwise fine.
While giant slalom is usually Vonn's worst event, she had posted the fastest split times until her crash.
"I was hoping for something today," Vonn said. "I was charging, I was skiing hard. I'm disappointed in myself now that I made that mistake. I can only keep smiling. I know I was skiing well."
"One hundred percent, absolutely," Vonn's coach, Jim Tracy, told Reuters when asked what the chances were of the downhill gold medallist and standout skier of the U.S. women's team competing in Friday's slalom.
"She'll race. Too much drama," he added.
"She's had way worse than that (injury). She'll be fine."
Julia Mancuso was the next starter after Vonn and had to restart her run when Vonn crashed. She finished out of the top 10.
Mancuso was flagged down and had to make her way back up to the top of the course for a later start, which usually is tougher with the course deteriorating as one skier after another comes down.
Restarting is also a test physically and mentally.
"Well now its time to use that anger and fight second run!" Mancuso wrote on her Twitter account between runs. "That yellow flag in the GS was such ... I just want to scream. I'm really miffed. Anyway, gotta take that energy and focus it for 2nd run."
Vonn said she felt "terrible" for Mancuso, a rival since they were kids.
"She's mad, she's frustrated, she's probably mad at me," Vonn said. "I feel terrible, and I hope she understands. I definitely didn't want that to happen."
All four Canadians have made the flip, led by Shona Rubens in 22nd place. Marie-Michèle Gagnon is 23rd with Marie-Pier Préfontaine 27th and Britt Janyk 29th.
"Obviously, were disappointed that we didn't race (the second run.) We were ready, all four Canadians," said Gagnon. "But we'll be better tomorrow. For the second run tomorrow, we will be ready again."
Goergl took bronze behind Vonn and Mancuso in the downhill that opened the women's alpine portion of the Games. She has won three World Cup races in her career, two in giant slalom — but the last nearly two years ago.
Barioz' best finish in any discipline was third in a giant slalom in Lienz, Austria, in December.
Zettel opened her Games by finishing fourth in the super-combined. A technical specialist, she is second in this season's World Cup giant slalom standings, having won the GS in Maribor, Slovenia, last month.
Tina Maze of Slovenia — who took silver in super-G — was fifth.
German standout Maria Riesch was seventh, 0.48 second behind Goergl; Swedish great Anja Paerson was 12th, .89 out, and Tanja Poutiainen of Finland was 13th, with 1.04 to make up.
"The visibility was pretty bad. We could see about three gates so you really had to trust yourself," Paerson said. "I think I have a good chance of taking a medal here, but then I really have to charge in the second run."
Sarah Schleper of Vail, Colo., was the top American finisher in the opening run in 14th, 1.07 back. SRC
— The Canadian Press and Alpine Canada contributed to this report
