Shiffrin in control after World Cup giant slalom first run
Shiffrin was a massive 1.60sec faster than discipline leader France's Tessa Worley and 2.10 sec faster than Sweden's Sara Hector in Meribel in the French Alps.
The 27-year-old from Colorado has already won the women's overall World Cup title, picking up that honour for the fourth time in her career on Thursday.
Finishing second in the Super-G in Courchevel on Thursday she took an unassailable 236-point lead over her closest rival, Slovakia's Petra Vlhova.
It was a remarkable comeback after a series of disastrous performances at the Beijing Winter Olympics, where she failed to win a medal.
Shiffrin won three straight overall World Cup titles from 2017 to 2019 before the death of her father Jeff in 2020 led to her taking most of that year off.