Mowinckel continued the form she showed in taking downhill and giant slalom silver medals at last month's Winter Olympics in Pyeongchang to clock a winning time of 2min 34.80sec across her two runs.

Home favourite Viktoria Rebensburg finished second on the German course in a distant 2:35.46.

Shiffrin finished a further 0.08 seconds behind in third place.

Switzerland's Wendy Holdener had been the only skier with a mathematical chance of catching Shiffrin in the overall stakes if she finished in the top two. 

Holdener finished 14th today, however, to leave Shiffrin with an insurmountable 603 point lead. 

The American duly wins for the second successive season with five races still remaining. 

Tessa Worley of France finished 13th today but still leads the giant slalom World Cup standings with 663 points.

Shiffrin sits second, on 657, and Rebensburg third on 607.

Attention will now turn to a slalom race tomorrow. 

A men's downhill race is also scheduled for Saturday in the Norwegian resort of Kvitfjell.

Beat Feuz of Switzerland heads the men's downhill rankings by 40 points from Norwegian rival Aksel Lund Svindal.

Dominik Paris of Italy is currently third.