They humiliated reigning premier Port Adelaide at Subiaco Oval last Sunday winning by 117 points.
West Coast had the luxury of 16 goal-scorers - equalling the VFL/AFL record, a feat achieved only twice before.
The 27.17 (179) to 9.8 (62) result leaves the Power stranded on just three-and-a-half wins after 10 rounds, and facing an uphill battle just to qualify or the finals, let-alone defend their crown.
For West Coast, the result gets them back on the winning track and takes them two games clear on top of the ladder with the club fighting for a top-two spot - and home finals - come the end of the season.