The Bulldogs were the only team to beat Essendon last year, but the Bombers enjoyed sweet revenge as they ran out winners 24.10.154 to 11.10.76.
In an amazing first-half performance, Moorcroft had 11 kicks, nine marks, booted six goals and had six opponents, capping his show with a brilliant high mark that immediately assumed favouritism for mark of the year.
The red-headed forward took eight of his nine marks inside 50m, and should have kicked nine goals in the first half rather than 'just' six.
He saved the best for last, leaping to put his feet on Johnson's shoulders and taking a mark while hovering almost horizontal with the ground, six feet in the air.
The Bulldogs kicked the opening two goals of the match to raise hopes of another upset win, but the reigning premiers rattled on 12 goals to three for the remainder of the first half to effectively end the contest.
Bulldogs utility Rohan Smith was knocked out early in the third quarter while running with the flight of the ball in an attempted mark and was collected high by Bomber defender Sean Wellman.
Smith suffered a severe concussion and was taken to hospital for observation.
Despite being comprehensively outplayed, the Dogs trailed by only six goals 15 minutes into the third term and had some hope of revival, but the Dons were not about to yield control and kicked away for an easy win.
Moorcroft was barely sighted in the second half, but remained among the best on the night, along with Joe Misiti and Mark Mercuri - both back near their best after knee injuries.
It was the Bulldogs' second straight heavy loss after the mid-season break, and the resultant percentage drop could prove critical in their race for a lower spot in the eight.
Scoreboard:
ESSENDON: 5.3, 12.6, 19.7, 24.10 (154)
WESTERN BULLDOGS: 3.2, 5.3, 10.5, 11.10 (76)
Goals: Essendon: G Moorcroft 6 M Lloyd 5 S Lucas 3 M Johnson 2 M McVeigh 2 B Caracella 2 D Solomonn A Ramanauskas J Barnes D Rioli. Western Bulldogs: B Johnson 3 L Darcy 2 C Grant S Garlick P Hudson P Curley N Brown C Ellis.
Best: Essendon: G Moorcroft J Misiti M Mercuri M Lloyd B Caracella A Ramanauskas P Barnard. Western Bulldogs: L Darcy N Brown S West C Grant.
Injuries: Essendon: D Hardwick (Chest) replaced in selected side by J Bannister. J Johnson (ill) replaced in selected side by M Bullen. J Barnes (groin). Western Bulldogs: R Smith (concussion).
Reports: Nil
Umpires: M Ellis D Goldspink B Sheehan
