Three-time Perth Cup (2400m) winning jockey Patrick Carbery admits he wasn’t sure what to expect from Hemlock Stone in yesterday’s edition of the staying feature at Ascot.

Hemlock Stone scored an upset win the $1 million feature and delivered trainers Grant and Alana Williams a fifth win in the past seven editions of the race.

The five-year-old was sent out one of the rank outsiders with betting sites at $81 for the Group 2 event but saved his best performance for when it mattered most to outlast the more fancied Diamond Scene.

Carbery, who won the Cup aboard Lotilla Bay in 2001 and Midnight Blue in 2022, rode the gelding for the first time yesterday and said he was glad he put it all together at the right time.

“His last run wasn’t terrible, but he still had to elevate quite a bit,” Carbery told TABradio.

“Doing his video form going into the race I thought I was on a quirky horse.

“I thought there was three of him and I wasn’t sure who I was going to ride.

“I’d never sat on him before, and he was an absolute marvel.”

Yesterday’s Cup time of 2:27.33 was the second fastest behind Guyno (2:25.99 in 2009) since the distance was reduced to 2400m.

Carbery said the strong speed ensured Hemlock Stone had every possible chance.

“He relaxed really well,” he said.

“It was a good tempo and I got on the right ones back and he pretty much outstayed them.

“To his credit, he was strong through the line.

“It was a genuine staying test, and I think that’s what brought a few of them undone.”

While Hemlock Stone was one of the outsiders in the field of 15, Carbery said he knew better than to doubt the Williams stable’s ability to get the stayer right for the day.

“The thing I was positive about was I was riding for a team that could get their horse to the big races in great order,” he said.

“Their record speaks for itself and that’s probably what I was banking on.

“They obviously work well as a team and have great staff behind them.”