Despite being bolstered by the likes of premiership hero Dom Sheed and midfield bull Elliot Yeo, the Eagles were beaten convincingly by 78 points at Leederville Oval.
After booting the first two goals of the match, East Perth stormed home kicking 11 straight to clinch an easy victory 18.10 (118) to 6.4 (40).
Hugh Dixon reached rare air with three majors in his first match as a WAFL Eagle and was West Coast's lone goal scorer until midway through the third stanza, when Josh Burke finally broke the drought.
This handed the Eagles some needed momentum, with Jack Williams kicking a terrific snap over the shoulder and Darby McCarthy also narrowing the deficit with one of his own.
It was also fantastic to see Sheed (18 disposals) in action after four months on the sidelines, with the prolific wingman showing good signs on managed minutes.
Tall forward Dixon was also extremely influential to finish as one of the Eagles' best, while Yeo built his match fitness across half-back.
Pacey utility Patrick Naish also saw a lot of the ball, finishing with 21 disposals, four marks and three tackles in the first two quarters, before heading to Optus Stadium at half-time to be used as the AFL Emergency.
After winning the third term - and narrowly losing the first - it was the second and final stanzas which let down the Eagles, with East Perth booting 12 majors and holding West Coast goalless across these two quarters.
Despite the tireless effort from skipper Zane Sumich (15 disposals, eight marks, four tackles) in the backline and the enthused performance from best Eagle afield, Joey Deegan (28, four, three), West Coast were overrun on the Royals' home turf.
In positive signs, exciting youngster Zane Trew also continued to improve his craft after spending nine months on the sidelines with stress fractures in his back and shin splints.
He recorded 14 disposals and laid a sizeable eight tackles and will only continue to improve with more game time.
Injury-hit forward Oscar Allen also spent time in the coaches' box, while fellow teammates Campbell Chesser, Xavier O'Neill and Tom Cole supported from the sidelines.
WEST COAST 2.2 2.3 6.4 6.4 (40)
EAST PERTH 3.1 11.1 14.5 18.10 (118)
GOALS
West Coast: Dixon 3, Williams, Burke, McCarthy
East Perth: Brayshaw, Kuek 3, Schumacher, Dittmar, Sparks 2, Ramsay, Wright, Robertson, McGuire, Jones, Watts
BEST
West Coast: Deegan, Levien, Hansen, McCarthy, Sumich
East Perth: Schumacher, Scott, Wright, Sparks, Brayshaw
