Gai Waterhouse will have a runner she believes can stem the European tide in the Melbourne Cup with Cismontane sealing his place with victory in the Lexus Stakes at Flemington.

Saturday's Lexus over 2500 metres, three days before the Cup, is the last chance to earn a guaranteed berth and Cismontane's staying credentials were truly tested with Stephen Baster sending him straight to the front.

He set up a strong tempo and just when it looked as if he would be swamped, the five-year-old kept going to the line to dent the Cup dreams of connections of Vengeur Masque who finished a short neck second with Pentathlon, who briefly looked the winner, another short head third.

"It's so exciting," Waterhouse, who trains in partnership with Adrian Bott, said.

"He will go to the Cup. That's been the plan all along."

Waterhouse won the Cup (3200m) four years ago with the imported Fiorente but Cismontane is a throwback to the colonial breed by shuttle stallion High Chaparral out of New Zealand mare Viviane.

Vengeur Masque's trainer Mike Moroney said his owners would pay up in the hopes of a Cup start because of attrition with doubts over Jon Snow who has yet to pass a veterinary examination.

Jon Snow's co-trainer Murray Baker says he will pay up and let the Victoria Racing Club decide whether the Australian Derby winner takes his place.

Fellow New Zealand trainer John Wheeler is resigned to missing the Cup with Pentathlon.

The Melbourne Cup field will be decided late on Saturday afternoon.

The TAB cut Cismontane from $151 to $31 for Tuesday's Cup.