Cummings, who joined his grandfather Bart and brother Edward as an Australian Cup winning trainer, may now head to the Group 1 Queen Elizabeth Stakes (2000m) at Randwick on April 8 with the imported galloper who started his career in France.
Sent out the $4 favourite under Ben Melham, Cascadian weaved a passage in the straight to score a three-quarter length win from Numerian ($11) with Pounding ($26) the same margin off third.
Cascadian was backing-up from an unlucky second in the All-Star Mile at Moonee Valley last Saturday.
"He deserves another big Group 1," Cummings said.
"He's a wonderful horse and he's a credit to his Highness Sheikh Mohammed to be winning a big weight-for-age race on a big day in Melbourne at Flemington.
"I suppose I could run the horse in three weeks in the All Aged - he's so adaptable, he'd run well - but that is looking like one of the races of the carnival.
"I don't mind the idea of laying away in the Queen Elizabeth and saving for him for a turn of foot and if he gets through, he gets through and he might give the Japanese (Unicorn Lion) horse a scare.
"One thing about Cascadian, he beat Montefilia third-up last prep over 2000 (metres) by further than Dubai Honour, so he might beat Dubai Honour.
"He's a great horse Cascadian, he's now a Doncaster winner, an All-Aged Stakes winner and he pops the Australian Cup on his mantle."
Cascadian provided Melham's partner Jamie Kah with her maiden Group 1 success in Sydney when he took out the 2021 Doncaster Mile and Melham has been aboard the eight-year-old in only two starts.
Melham first rode Cascadian in the All-Star Mile last week and after looking at replays of his runs at Flemington realised he was a horse that need to be smothered away.
"We wanted to duck and weave on him because, watching his tapes, we feel that's how he races best," Melham said.
"Being wide and exposed, he's had a lot of goes here at Flemington and he's never won one.
"He's such an honest horse and to be on the quick back-up from the mile to the 2000 (metres) and going to the gates he was that bloody fresh I nearly couldn't hold him.
"James has done a tremendous job to bring him here in that condition and to back up his All-Star Mile run with a sensational win like this is fantastic."
