Bullish Stock has reaffirmed his trainer's belief he has a future as a stayer with a strong win at Sandown.

The three-year-old failed to make the Victoria Derby field but David Hayes is eyeing off interstate Classics in South Australia and Queensland.

Ridden by Craig Williams, Bullish Stock ($6) won Wednesday's Cove Hotel (1800m), beating Maxie's Blue Girl ($8) by a neck with the favourite O'Lonera ($3.50) another 1-3/4 lengths third.

"He is a promising horse and we are looking at races like the South Australian Derby and Queensland Derby," Hayes said.

"He didn't make it to the Victoria Derby but he is a promising horse."

Hayes said although Bullish Stock had been racing since September, he and co-trainer Tom Dabernig would more than likely keep him in work instead of sending him to a paddock ahead of the two Derby races in May and June.

Williams said it was a solid win and showed the gelding had maintained his fitness.

Another horse to please the jockey with his fitness is Criterion who runs in the Hong Kong Cup on Sunday week.

Williams will be reunited with Criterion who he last rode to win the $4 million Queen Elizabeth Stakes in the autumn.

"I was part of his last two pieces of work before he left for Hong Kong and he was in good order," he said.

"I'm looking forward to it."

The jockey will be part of Saturday's State of Origin racing at Doomben before he flies to Hong Kong early next week.

Williams has ridden Criterion in Hong Kong twice for third place finishes in he 2014 Cup and the QEII Cup earlier this year.