Mikaela Shiffrin was disqualified from the giant slalom on Monday as her Winter Olympics began in disappointing fashion.

The defending champion missed a gate and fell on her hip only five turns into her first run at the challenging course known as the Ice River.

It was a rare error from the United States star, who has three Winter Olympic medals including two golds. She is bidding to become the first American to win three golds at the Games in alpine skiing.

Shiffrin has only failed to finish 14 times in 229 starts across all disciplines at World Cup, Olympic and world championship events and was top of the overall World Cup standings coming into Beijing.

"I won't hide the disappointment, but I'm not going to dwell on it because that won't help me," she said.

"I felt that I was pushing really quite well and attacking. But there was just one turn, I had a small, small mistiming when I really went to push on my edges and that makes all the difference.

"I have been really working on the right timing of my turns and really never thought this was going to be part of the issue. But it wasn't because I was holding back, so I can be proud of that. But it's five turns into the Olympic GS, there's disappointment for sure."

In total, there were 19 DNFs among the 80 starters in round one alone, including last year's World Cup winner Marta Bassino.

Sweden's Sara Hector took gold at the end of the second run, ahead of Federica Brignone and Lara Gut-Behrami.

Shiffrin, who will compete for five more medals at these Games, will next be involved in the slalom on Wednesday.