Harry Bentley is convinced Unbelievable will produce his best run in Hong Kong when the impeccably bred colt contests Sunday’s BMW Hong Kong Derby (2,000m) at Sha Tin.

Unbelievable arrived at Frankie Lor Fu-chuen’s stable with massive expectations as a full brother to Europe’s champion juvenile of 2023, City Of Troy, and a two-time winner for champion trainer Aidan O’Brien when known as Bertinelli.

However, the Justify colt failed to flatter when 12th in his Hong Kong debut over 1,600m last month before running an improved eighth to Helios Express in the Classic Cup (1,800m).

Set for his first race ride on Unbelievable, Bentley said the four-year-old had excuses in his first two runs in the city and was primed to show his true colours in the Derby.

“I really like him. To be honest, I’m delighted to be on him. I think he’s one that probably flies under the radar a little bit,” Bentley said.

“He’s had two runs now, which I think will have straightened him up, and up to 2,000m is well within his comfort zone.”

Under Derek Leung Ka-chun, Unbelievable was trapped wide without cover for most of the Classic Cup but fought on solidly to only finish two lengths behind third placegetter Ensued.

“I think he’s just one that comes in a little bit under the radar and hopefully he can take a step forward from that Classic Cup run, which I thought was actually pretty good,” Bentley said.

“The fact they went so slow in the mid-part of the race would not have suited him at all and Derek just had to come out and get him rolling. With a stronger pace, I think you could have upgraded that run.”

Bentley had his first sit on Unbelievable in a 1,700m trial at Happy Valley last week, in which Lor’s charge ran fourth behind Straight Arron.

Under the guidance of O’Brien, Unbelievable won a 1,600m maiden in Ireland and the London Gold Cup (2,000m) at Newbury.

His final start for the master handler was a sound third to Desert Hero in the King George V Stakes (2,392m) at Royal Ascot last year.

“Obviously he’s an extremely well-bred son of Justify and there’s stamina there as well on the dam’s side,” Bentley said.

“He’s certainly bred for this distance and to go further. His win in the London Gold Cup at Newbury was a good win and it’s strong form. That race always turns out Group horses and then subsequently he went on to finish third at Royal Ascot.

“He’s a classy horse and I know he came here with a good bit of expectation on his back. A lot of people could easily perhaps be disappointed with what he’s shown so far, but I think you can take those runs with a pinch of salt and his first run was over way too short. He’s an exciting horse.”