Clark was one of the few shining lights for Melbourne.
He booted two in succession and had five goals by the end of the match.
Aside from Clark’s efforts, and midfielders Nathan Jones and James Magner, who battled manfully, there were few winners.
James Frawley down back also kept Josh Kennedy quiet, after the Eagle booted seven goals last week.
In the end, the Eagles smashed Melbourne by 108 points.
It was West Coast's greatest winning margin over the Demons.
WCE 25.16.166 d Melb 9.4.58
Third quarter
The Eagles extended their lead with the opening three goals of the second half.
Jones halted that run with his second and Melbourne’s first for the third term.
But West Coast took it to another level, with five goals to one for the remainder of the term.
Jack Darling kicked three goals for the quarter to have four entering the last term.
Mitch Clark had three of Melbourne’s six majors.
West Coast took a 90-point lead into the final term.
Second quarter
The Demons kicked two of the first three goals of the term to peg the margin back to 16 points.
Nathan Jones and Mitch Clark booted one each.
But the Eagles upped the ante, booting six of the next seven goals to break away to a 48-point lead at half-time.
There were few Melbourne highlights in this period except for Clark's second - a snap around the body - and Jeremy Howe's high-leaping mark.
West Coast's Ashton Hams and Quinten Lynch booted two goals each for the term, while Scott Selwood added his second for the match.
James Magner had 19 disposals to lead Melbourne's possession count at the long break.
WCE 11.8.74 to Melb 4.2.26
First quarter
WEST Coast kicked the opening goal of the match via Luke Shuey.
WCE 4.3.27 to Melb 1.1.7