The Irish-bred galloper finished fourth to be only one of two Australian-trained gallopers to finish in the top 10 and collect a prize money cheque.
Weir, who won the 2015 Cup with Prince Of Penzance, said pre-race he was hoping for a top-10 finish with Big Duke who finished third in this year’s Sydney Cup.
“He’s run a great race,” Weir said.
“He’s usually so honest and to finish in the top five is a great result.”
Big Duke was one of three runners Weir saddled in the race.
Weir said he would need to look at the replay to get a better indication of their performances.
“Humidor, he looked like he ran well below expectations while Amelie’s Star was caught wide and didn’t get in but I need to look at the replay again.”
The Chris Waller-trained Libran finished eighth to also collect a prize money cheque for Australia.