Lightweight chance Vow and Declare, the only Australian-bred runner in Tuesday's Melbourne Cup, held off a legion of foreign rivals to win Australia's greatest horse race for its local trainer, jockey and owners.
The 11-1 shot hugged the running rail in the last stages of the two mile handicap to just hold out Ireland-trained Master of Reality, ridden by star jockey Frankie Dettori who, in a glittering career, has yet to win the $8 million ($5.5 million) Melbourne Cup.
In a sensation after the race, Master of Reality was relegated from second to fourth place for causing interference to another Ireland-trained runner, Il Paradiso, which was fourth across the line.
Master of Reality is trained by Joseph O'Brien at Kilkenny and Il Paradiso by his father, famous trainer Aiden O'Brien. Joseph O'Brien won the 2017 Melbourne Cup with Rekindling, edging out his father's runner Johannes Vermeer.
The relegation of Master of Reality saw England-trained Prince of Arran promoted from third to second place and Il Paradiso to third.
Vow and Declare endured the bumping finish to deliver a first Cup victory for his Australian trainer, Danny O'Brien and also the first for Australian rider Craig Williams in 15 attempts.
O'Brien said the task of winning the Melbourne Cup against runners from Britain, Ireland, Japan and New Zealand had "a bit of David and Goliath" about it.
"It's a special thing to happen and I really can't believe it," O'Brien said. "It's a privilege to have a horse good enough to be in it and then for him to be ridden so brilliantly by Craig.
"In the last stages he just wouldn't give in and wouldn't give in and he put his head out on the line and won the Melbourne Cup."
Starting from the second-widest barrier in the 24-horse field, Vow and Declare ran prominently throughout the race and took the lead down the long straight at Melbourne's Flemington racecourse as a crowd of more than 100,000 roared. Master of Reality challenged wider on the track and Prince of Arran flashed home late but the only Australian-bred hope held on.
"I was just lucky enough to sit on Vow and Declare," Williams said. "Without the hard work of everyone at the stable we don't have this horse.
"Danny O'Brien's done a wonderful job with him and it was a privilege to ride him today. We had a difficult barrier draw and I just had to trust him and know what we can do. It's great to be associated with a great horse.
"The bit of bumping that he endured late actually spurred him along. I grew up and watched races, wrote stories, dreamed of these occasions. But I couldn't do it without Vow and Declare."
The Melbourne Cup, raced since 1861 on the first Tuesday in November, is known as "the race that stops a nation." The race begins at 3pm and Australia comes to a standstill as people in workplaces around the nation, including the national parliament, gather around televisions to watch.
The fields for the race have become increasingly international in recent years and Australian winners have become rare. Vow and Declare is owned by a group of small-time owners, mainly from Australia's east coast.
It was No. 23 in a 24-horse field.