Dolan delivers in the Lexus Melbourne Cup

A once part-time jockey who flirted with a career as a musician added his name to the Melbourne Cup honour roll when he engineered one of the great upsets in the history of the great race.

Ireland's Robbie Dolan partnered $91 chance Knight's Choice to a thrilling win in the $8.5 million Group 1 at Flemington on Tuesday.

Dolan came to Australia in 2016 in search of better opportunities and experienced great success with Profondo and Shelby Sixtysix, who won Group 1 races in 2021 and 2022, before striking national recognition trough talent show The Voice.

Dolan's previous biggest moment on the big stage in Victoria was singing 'Horses' at the 2022 Cox Plate, but he put that to shame with his Melbourne Cup win.

"Well, pinch me, I think I'm dreaming," he said.

"I can't even put it into words. This is the biggest race in the world, and to win it is just incredible.

"I've never ridden this race before, so I didn't know what to expect, but I feel like I've ridden it 10 times because I've run the race over in my head before I got here.

"It panned out exactly as I thought it would."

Dolan won the race in front of his partner Christine and young daughter Maisie, along with his father Bobby who spent decades working for two-time Melbourne Cup-winning trainer Dermot Weld in Ireland.

The 28-year-old turned in a ride for the ages to get the John Symons and Sheila Laxon-trained gelding home.

Knight's Choice, a son of Newgate stallion Extreme Choice, settled towards the rear but started to improve towards the inside when a number of leading chances who were also back in the second half of the field made their move out wide from the 500m.

The five-year-old surged alongside eventual runner-up Warp Speed over the final 300m and hit the line a half-head clear that Japanese galloper, a $26 chance who was ridden by Akira Sugawara.

Completing a longshot trifecta, three-quarters-of-a-length away, was Jamie Kah's mount Okita Soushi ($19).

"I thought I'd be a pair closer, but they went quick, so I just rode him for luck because I know he's got a good turn of foot," Dolan said.

"Once my horse spotted the gap and he sort of changed leads, he just picked up on me.

"Once I pulled the stick through, he found another gear again.

"He's only a small little horse, but he gives his all every start, and that's half the battle with him.

"I think and he's proved a lot of people wrong."

Dolan became the second Irishman to win the Melbourne Cup, 31 years after Michael Kinane won aboard the Weld-trained Vintage Crop.