“Pinch me, I’m dreaming… I can’t believe it,” he told the local Nine Network.
“I think I’ll be singing for the rest of my life after that. What the hell.”
The 28-year-old comes from a horse racing family, with his father Bobby Dolan part of Irish horse training legend Dermot Weld’s team when they produced two Cup winners in 1993 and 2002.
Bobby surprised his son by travelling to Australia for his Melbourne Cup debut, and was in the crowd to watch his victory.
It was also a family affair for Laxon, who trained Knight’s Choice with her husband John Symons and lifted the trophy 23 years after her first victory, when she became the first female trainer to win with Ethereal.
Absurde was fifth for Irish trainer Willie Mullins, with his stablemate Vauban 11th. British challengers Onesmoothoperator and Sea King finished 12th and 14th.
Crowds thousands-strong were trackside at Flemington for the event, decked out in bright outfits and enjoying the sunny spring weather.
The Melbourne Cup is worth more than A$8m (£4.1m, $5.3m) and is often called “the race that stops a nation” although has attracted demonstrations in recent years over animal welfare.