In a year that has been like no other, Irish trainer Joseph O'Brien has watched his horse win Australia's most famous race from the other side of the world.

It was the wee hours of the morning in Ireland and after a fitful, anxious sleep,Joseph O'Brien rose in the dark to watch his two Melbourne Cup runners.

Unable to be at Flemington due to COVID-19 travel restrictions, the young Irish trainer had to content himself with looking on via a screen.

But it would have made for exciting viewing as the O'Brien-trained Twilight Payment led from start to finish to give him his second Melbourne Cup, three years after Rekindling captured his first.

"I nearly couldn't sleep thinking about the race," O'Brien said.

"It's a pity we can't be there but we're very lucky to be able to take part in the race this year."

Not for the first time, O'Brien relegated his father, training wizard Aidan O'Brien, to second place with Tiger Moth.

The older O'Brien, who has been trying to add the Melbourne Cup to his incredible international haul of major races for years, also finished in his son's wake in 2017 with Johannes Vermeer, who was runner-up to Rekindling.

Joseph O'Brien was a diplomatic winner on Tuesday.

"Some days I'm lucky enough to win, some days he's lucky enough and that's racing," O'Brien said.

Eight of the 23 Melbourne Cup runners came from European stables and they ran the trifecta with Twilight Payment staving off Tiger Moth and the Charlie Fellowes-trained Prince Of Arran.

Joseph O'Brien's other runner, Master Of Reality, finished 15th.

While Twilight Payment was sent out a $26 chance, O'Brien and jockey Jye Mc Neil had faith in their horse, hatching a plan to run their rivals off their legs.

"We had a good chat with Jye and Jye had a very clear plan in his head of what he wanted to do and we felt that, if we had to make the field come and get him, they might struggle to catch him and that's how it worked out," O'Brien said.

"The one thing that Twilight Payment has is an incredible will to win."

It was a case of what might have been for Fellowes after Prince Of Arran stormed home for another Melbourne Cup placing after finishing third to Cross Counter in 2018 and runner-up to Vow And Declare last year.

"We just got caught behind a wall of horses at the wrong point and he just got out a bit too late," Fellowes said.

"He's run a massive race again and he's an incredible horse.

"We finished third in a Melbourne Cup so I'm not gutted at all, I'm incredibly proud of him."

However, Fellowes also had some sage advice for Joseph O'Brien.

"To win two Melbourne Cups aged 27 is remarkable but he better not make a habit of this because other people want to win it as well."