They kicked in to gear in the final term though, kicking six goals, including the last three of the game.
The last time they played Melbourne in Perth was last years preliminary final when the Demons failed to show up. Melbourne scored 0.6 in the first half time to trail the Eagles by 63 points.
The Eagles were already plotting their premiership victory in the second half as the Demons steadied and lost by just 66.
Melbournes first goal came a lot quicker on Friday night, with Nathan Jones hitting the scoreboard two minutes into the game.
They held on to hold a four-point advantage at half-time and by 12 points at the last break.
But their disposal let them down and they were wasteful in front of goals. They led by 19 points in the third term, but then started to overuse it.
They had 15 more inside 50 entries than the Eagles and four more scoring shots.
Welcome back Willie
The Eagles welcomed Willie Rioli back from a foot injury for his first game of the season.
After the Demons started so well, it was Rioli who gave the home side the lead for the first time. His first touch for 2019 was 11.30 minutes in to the game, when he stole the ball from the Melbourne defenders and dribbled it along the ground and through the big posts from 40m out.
Two minutes later, Kennedy earned a free kick at a stoppage 30m out right in front and kicked his second to give the eagles a nine-point lead.
The Demons kept to their game plan though, which was to move the ball quickly into attack.
Clayton Oliver, Jones and James Harmes were keeping the play going and Tom McDonald and Christian Petracca were providing good targets.
Max Gawn dominated in the ruck against Nathan Vardy and Tom Hickey. Gawn finished with 56 hit outs and seven clearances.
Unfortunately for the big fella, his part in the highlight reel will be as a step ladder for the high flying Liam Ryan in the Eagles goal square late in the final quarter. The spectacular mark and goal gave the Eagles the lead for the last time.
Out of attack
Jake Melksham went into this game the only Demon to have 10 goals next to his name, but he didnt make the trip. Melbourne needs to find more avenues to goal.
Going into this Round 9, they had kicked just 80 goals, with only Gold Coast (70) having scored fewer.
They are bleeding at the other end as well. Their 110 goals against them before Friday night was the second worst after Round 8, with North Melbourne having conceded 111.
Jeff Garlett kicked three goals against the Eagles and Petracca two, but that pair and Tom McDonald also slaughtered chances they should have kicked.
Season on the line
There are serious doubts about Melbournes chances of playing finals now. The expectations to do so come on the back of them making a preliminary final appearance last season.
They could get there with just 11 wins this season, but that means they need to win eight of their remaining 13 games.
They have three big games ahead of them before their bye, against GWS, next Sunday at the MCG, then Adelaide (Darwin) and Collingwood (also at the MCG).
All three could be finals bound, which is a problem for the Demons.
It was Round 22 last season when they beat West Coast at Optus Stadium. That was their first win against a team that finished in the top eight.
They had lost all six of their previous games against teams that ended up seeing September action.
Of the 14 games they won to make the top eight, only two of them were against other top eight teams.
This season, they have a 3-6 record and have played only two games against teams currently in the eight the 80-point loss to the Cats in Round 2 and the Friday nights loss to the Eagles.
WEST COAST 3.2 5.4 7.6 13.7 (85)
MELBOURNE 3.4 5.8 8.12 9.15 (69)
West Coast: Kennedy 4, Cripps 2, Shuey 2, Rioli 2, Sheed, Darling, Ryan. Melbourne: Garlett 3, Petracca 2, Hunt 2, Jones, Smith.
West Coast: Hurn, Yeo, Sheed, Kennedy, Gaff, Shuey
Melbourne: Gawn, Harmes, Oliver, Garlett, Hunt, Petracca
Umpires: Jeff Dalgleish, Dean Margetts, Leigh Fisher.
Crowd: 51,162 at Optus Stadium.