Champion trainer Chris Waller is firming to win his first Melbourne Cup as Finche assumed favouritism on the eve of Australia's most famous race.

Japan's Mer De Glace had been at the top of markets since drawing gate two in Saturday's barrier draw but by late Monday he was displaced as favourite by Finche who was backed from $9.50 into $8.

Along with Youngstar, Finche is one of two Cup runners for Waller and will be ridden by three-time race winner Kerrin McEvoy.

McEvoy, who has won two of the past three Melbourne Cups, is shooting to become the first jockey to snare the race back-to-back since Glen Boss' three-peat aboard Makybe Diva in 2003-04-05.

He rates Finche a genuine chance.

"It's a race that captures our imagination as young kids wanting to be jockeys and being a part of this great industry, and I've been blessed enough to win it three times," McEvoy said.

"I'm thrilled about that and hopefully we can give it a shake tomorrow."

Melbourne's major spring races have so far been dominated by the Japanese.

They have won the Caulfield Cup with Mer De Glace and Cox Plate with Lys Gracieux, both ridden by Australian Damian Lane.

The 25-year-old will become just the eighth jockey to claim Australian racing's grand slam of the Golden Slipper (Kiamichi), Caulfield Cup, Cox Plate and Melbourne Cup if successful on Tuesday.

Of more significance, he will be the first to achieve it in a calendar year.

"Just to compete in the grand slams is a great thrill," Lane said.

"To be able to have won three of them, it's been an amazing year."

Lane's only concern with Mer De Glace is soft ground because the horse has never raced on a rain-affected surface.

Craig Williams is also chasing the final piece of the grand slam jigsaw having claimed a Slipper, Cox Plate and two Caulfield Cups.

He has missed out in 15 previous Melbourne Cup rides.

Suspension cost him the winning ride on Dunaden in 2011 but in Vow And Declare he has an undeniable opportunity.

"Dunaden was my best chance but I was suspended and I've had nice horses before and since," Williams said.

"But he's a great chance and I'm looking forward to it."

Cox Plate fourth placegetter Magic Wand was the biggest betting firmer on Monday from $26 into $19 despite having the outside barrier in 24.

She is also unproven at the distance and prefers dry ground but jockey Ryan Moore says she has the quality to win.

"She's a very high-class filly but she's running the distance for the first time and I wish it wasn't raining really," Moore said.

Magic Wand is one of three runners for champion Irish trainer Aidan O'Brien in his quest for an elusive Cup win.