The 23-year-old, who claimed a second consecutive World Cup overall title last weekend, led by 0.72 seconds having stopped the clock at 54.33 secs on the first run and stretched that lead to 1.58 secs with a hugely impressive 52.09 on the second run.
‘Absolute domination’ - Shiffrin secures 12th win of season
Switzerland’s Wendy Holdener was second with Sweden's Frida Hansdotter, who took gold in the slalom at PyeongChang, third.
Beaming Shiffrin receives her World Cup overall title
“My big focus was just trying to put two really good runs together,” Shiffrin said post-race.
“The first run, it was really quite solid, and for sure it was great skiing, but I felt like I had something else, like another level I could push.
“In the second run, I really did that, I skied it the way I imagined it should be skied. I was really pushing every single gate.”
Shiffrin already has 43 World Cup wins to her name.
LADIES’ SLALOM RESULTS
1 Mikaela Shiffrin 1:46.42
2 Wendy Holdener 1:48.00
3 Frida Hansdotter 1:48.01
4 Nina Haver-Loeseth 1:48.14
5 Bernadette Schild 1:48.21
6 Michelle Gisin 1:48.41
7 Katharina Gallhuber 1:48.47
8 Katharina Liensberger 1:48.57
9 Anna Swenn Larsson 1:48.61
10 Erin Mielzynski 1:48.62
Shiffrin tells Eurosport: I can look back and really smile about this season, I feel like deserve it
Hirscher smiles as he's handed seventh consecutive Crystal Globe