Mikaela Shiffrin heads into the Olympic slalom as many observer's favorite but her closest challenger, Slovakia's Petra Vlhova, says she now has the self-belief needed to end the American's dream.

The pair are set to clash in Monday's giant slalom before their highly anticipated battle on Wednesday.

Vlhova has won five-times in slalom on the World Cup circuit this season and has 17 career victories in the discipline but has never beaten Shiffrin in a world championship or Olympic slalom.

But Shiffrin, who has dominated in slalom for most of the last decade, has had just two World Cups in the discipline this season.

"For a long time Mikaela was better than me," Vlhova said. "However, in the last seasons I showed clearly I am able to beat her often. We respect each other because we both know very well how difficult it is to become the best in the world," she said.

Shiffrin won slalom gold in Sochi in 2014 but surprisingly failed to make the podium four years later.

The 26-year-old Vlhova said she has finally found the right psychological approach to the big races.

"I am now 100% mentally balanced, that was the only thing missing for me before to become really the best," she said.

"The season until now has been going very well for me, so I am in a very good mental mood and physical shape as well, and fully focused for the Olympic competitions. I feel really strong," she added.

The Slovak has also been boosted by top Swiss coach Mauro Pini joining her team in the off-season.

Pini had previously coached double Olympic gold medal winner Tina Maze of Slovenia and two-time world champion Lara Gut-Behrami of Switzerland.

"He created a very good atmosphere, allowing the team (to) work," Vlhova said.

"Everybody in the team knows what to do and the cooperation of all the people is great. Our communication in the entire team is very fruitful and there is a lot of fun among us. This is like when a complex puzzle is completed."

Sara Hector of Sweden heads the World Cup giant slalom standings ahead of France's Tessa Worley.