McGrath (21) beat Noël by 29/100 and the Swiss Daniel Yule by 64/100.
After crushing the first run, Austrian Olympic vice-champion Johannes Strolz missed out on the second track to finish 4th.
Only 16th, the Norwegian Henrik Kristoffersen keeps 48 points ahead in the classification of the specialty over his compatriot Lucas Braathen and 64 points over the German Linus Strasser before the last race scheduled in Méribel next week (the victory is worth 100 points).
Christmas can no longer claim the small globe.
Alexis Pinturault finished 14th at 1 sec 20.
© 2022 AFP