Gai Waterhouse is daring to dream about taking Imperial Aviator to the Melbourne Cup after the English import nailed his first win in Australia at Rosehill.

The trainer, who won her solitary Melbourne Cup with Fiorente in 2013, mentioned the race after the five-year-old gelding's success in the Tab.com.au Handicap (2400m).

"He's really going places. I can't see why in time .... we can dream about Melbourne Cups," Waterhouse said.

"He's only really learning the Australian way of racing but he'll keep improving. The penny's dropped."

Imperial Aviator relocated to Tulloch Lodge in October last year and Saturday's endurance test was just his third start since arriving.

Waterhouse and co-trainer Adrian Bott gave Imperial Aviator his debut in June at Randwick, where he trailed the winner by 18 lengths.

That performance led the training partnership to geld Imperial Aviator before he made his comeback with a second over 2000m at Rosehill two weeks ago.

"We held to geld him. He wasn't interested in being a racehorse as an entire. He's a different horse now," Waterhouse said.

The $2.50 favourite was given an astute ride by Josh Parr, who was happy to sit behind second-placed pacesetter Great Glen ($6.50) until he drew clear at the 100 to win by a length.

Last Wish ($18) improved from last at the 400 to cross three-quarters of a length back in third.

"It was a superb effort. Second start this preparation and he's done it like he was fifth up. He could be a very nice stayer," Parr said.