Shiffrin sets fastest time in opening world giant slalom run
The US star, who split with Mike Day on Wednesday after seven incredibly successful years, clocked 1min 02.54sec down the Roc de Fer piste in bright, sunny conditions.
"I actually thought I was a bit slower than everybody on the last bit because on these pitches this season I've always been a bit off," said Shiffrin, who bagged a super-G silver last week on the same slope.
"So when I was skiing I kept thinking 'No, you have to push harder, push harder, push harder', so I guess that was the right tactic in the end.
"My skiing felt really good and I think the most important thing was that I didn't make any big mistakes so I have to take a good balance of these tactics in the second run, smart skiing, but also full pushing.
"Everybody's had a run on the hill so everybody can step it up a notch."
Shiffrin, 2018 Olympic gold medallist in the GS, is perfectly poised to add to her 12 career medals at the world champs, including six titles (six gold, three silver, three bronze).
Only Germany's Christl Cranz (15), skiing pre-WWII, and Sweden's Anja Paerson (13) have claimed more world medals than the American.
A seventh world title would also see Shiffrin draw level with Paerson, Marielle Goitschel, Marcel Hirscher and Toni Sailer while Cranz has 12 to her name.
Second fastest down the opening leg, with the second scheduled for 1230 GMT, was France's two-time former champion Tessa Worley, at 0.12sec.
"A good first leg, the goal is achieved: to be in the mix and be able to give everything in the second leg to go looking for the title, the medal," said the 33-year-old French racer.
She was followed by a host of skiers capable of capitalising on anyone's mistake on the unforgiving course.
Italy's Federica Brignone, the Olympic silver medallist in the discipline and world alpine combined winner here last week, was third (+0.31), with Switzerland's defending world champion Lara Gut-Behrami fourth (+0.64).
Norway's Ragnhild Mowinckel was at 0.71sec, with Sweden's Olympic champion Sara Hector a further 0.25sec adrift.
Shiffrin's Slovak rival Petra Vlhova was exactly 1sec behind, in ninth spot, and has it all to do in the second run in her bid to push for a podium finish.
