Trainer Danny O'Brien has vowed to bring Vow And Declare back to defend the Melbourne Cup title next year.

The Australian-bred, owned, trained and ridden Vow And Declare repelled the international invasion to deliver an all-Australian Melbourne Cup victory and a slice of history for jockey Craig Williams.

O'Brien and Williams, who joined an elite group of jockeys to win Australian racing's “grand slam”, were proudly flying the flag for Australia against an army of international raiders.

It was a first Melbourne Cup for both.

O'Brien said the race had changed over the last decade, noting there were probably only five internationally trained contenders when he had Master O'Reilly in the Cup about a decade ago.

“This year there's 22. It's certainly become a more elusive target for a local trainer.

“To do it with a locally bred horse, again, it's not something that's going to happen very often.

“It is getting further and further out of reach but obviously today shows it can still be done,” he said shortly after winning on Tuesday.

O'Brien is already thinking ahead to next year's Cup for four-year-old Vow And Declare.

“He's a horse that we think ultimately he'll get better at five, six, seven.

“He's not going to be over-raced. He's had three runs this spring.

“We'll consider every possibility for him, but I would expect that the most likely thing for him now is to try and get back here for the race next year.”

Only five horses in the Cup's 159-year history have won the race twice – four of them winning back-to-back – including three-time winner Makybe Diva.

Williams became just the eighth jockey to claim Australian racing's “big four” of the Melbourne and Caulfield Cups, Cox Plate and Golden Slipper.

Williams was thrilled an Australian-bred and owned horse was the one to deliver his longed-for Melbourne Cup.

“To be lucky enough to be associated with an Australian-bred horse as the race is now so international, it's wow,” Williams said.

“It is very special to be able to win our greatest race.

“It just resonates with everyone. It stops the nation. It's very special so I'm very thrilled.”