UPDATE 2-Alpine skiing-Vonn slides out of Super G, Schmidhofer wins

* Flawless run by Austria's Schmidhofer

* Vonn struggles with pole

* Defending champion Veith crashes out (Updates with Schmidhofer win, quotes, details)

ST MORITZ, Switzerland, Feb 7 ( Reuters) - Lindsey Vonn's first run at the World Championships lasted just a few seconds on Tuesday when the American slid out of the Super-G in St Moritz with Austrian outsider Nicole Schmidhofer staging a major upset to snatch victory.

Starting 11th, Vonn was as good as her word, having said at the weekend she was going to go all out - win or bust. Despite a perfect start, it was the latter as she slid out mid-course, but managed to avoid a crash.

Defending Super G champion, Anna Veith, suffered a worse fate, crashing out of the race.

Vonn, though, picked herself up and skied to the finish zone where the 32-year-old was cheered loudly.

"I lost my pole early on and tried to get it back," she said. "I was distracted for a second and thought I lost a lot of time. I went too straight and had no chance of making the next gate."

"It was a tactical error but it tried to give everything. I am not disappointed. I tried as hard I could. I don't know why I am losing the pole. I will duck-tape it to my hand," Vonn said.

The four-times overall World Cup champion and 2010 Olympic downhill gold medallist says her best chance for a victory is in Sunday's downhill.

She has 77 World Cup wins under her belt, nine victories off the record number held by Swedish great, Ingemar Stenmark.

The 27-year-old Schmidhofer, who has never won a World Cup race, gatecrashed the first day of championships with a perfect run, shooting out of the gates and taming the icier parts of the lower course with skill to finish 1.21:34 minutes.

That dropped pre-race favourite Lara Gut of Switzerland to third and Liechtenstein's Tina Weirather to second.

"I had to do it today. I had very good training the last few days and I felt good," said Schmidhofer. "Today it was very good. I think it is a perfect run for me." (Reporting by Karolos Grohmann; Editing by Louise Ireland and Louise Heavens)