Mikaela Shiffrin produced a stunning performance to claim her third consecutive World Championship slalom gold in a row, topping the timesheet by 1.64 seconds.
The American led after the first run, before storming the course on the second run to finish comfortably clear of her nearest competitors.
The 21-year-old first won gold in this event four years ago, and having taken Olympic gold in this discipline during the Sochi games in 2014 she is starting to lay claim as the most dominant alpine skier in the world.
Wendy Holdener of Switzerland claimed silver to back up her gold in the combined event, with Sweden's Frida Hansdotter taking her third consecutive medal in this discipline with a brilliant bronze.
Italians capitulate as Shiffrin builds first run advantage
It was Shiffrin who had built an advantage after the first run, leading Holdener by 0.38 seconds. The Slovakian duo of Veronika Velez Zuzulova and Petra Vlhova were third and fourth, with Hansdotter in fifth, 0.77 seconds behind Shiffrin’s time.
Outside of the leading times, the big story after the first run was that of the Italian team having such a poor show. Chiara Costazza, Irene Curtoni and Manuela Moelgg each failed to finish the course, meaning Federica Brignone was the best of her nation’s skiers, finishing 26th, just one place ahead of Britain’s Alex Tilley who finished in the top 30 to qualify for the second run.
Another skier who failed to complete her first run was Melanie Meillard of Switzerland. With the St. Moritz crowd cheering her on, Meillard looked certain for a top 15 finish, before inadvertently missing the final gate just short of the line. The 19-year-old Swiss cut a disconsolate figure when passing through the winner’s enclosure after missing out on the opportunity of laying down a second run.
Shiffrin provides crowd with mesmerising run, storming to gold by 1.64 seconds
Sarka Strachova of the Czech Republic produced the second fastest time of the second runs to rise from ninth to fifth on the leaderboard, yet she had left herself too much work to do and finished just outside the medals.
Hansdotter was the only other skier alongside Strachova to finish within a second of Shiffrin's second run to jump ahead of the Slovakian duo, claiming her second bronze of the championships i the process.
Silver went to Holdener who recovered well late in her run to stay ahead of Hansdotter by 0.11 seconds, with Velez-Zuzulova's failure to finish ending her hopes of a medal.
That left Shiffrin with a 0.38 second lead at the top of her run, which she improved by more than a second despite skiing in the toughest of the conditions. The young American never looked like she would be beaten to become the most successful female slalom skier in the post-war period.
Sunday sees the final event of the World Championships, with Britain's Dave Ryding among the favourites in the men's slalom.