With the Classic Mile and Classic Cup already in the bag, Rapper Dragon has shown that he has the measure of most of his likely Derby opponents.

A step up to 2000m is something of an unknown factor, as is his stablemate Booming Delight who enters the Four-Year-Old Classic Series for the finale. The British import has made his way to a Derby berth with a hat-trick of wins that includes a Class 2 score at the course and distance last month.

The bay, sixth in the Britannia at Royal Ascot last year and a full-brother to G1 Racing Post Trophy winner Rivet, impressed this morning in batch 10, a 1200m trial over Sha Tin’s all-weather track.

“Booming Delight’s trial was a beauty,” Moore said. “And he loves that dirt surface, the way he moves on it.”

Once jockey Karis Teetan switched Booming Delight to the outside, his mount ran home smartly to clock 1m 11.20s in finishing fifth.

“They were going a bit slow so I just wanted him to have an easy trial, but he was very keen to get on with it,” Teetan said. “But he was travelling nicely enough behind them, and when I got to the outside and an open gap, he changed legs and he took off on me. He’s right on track for the Derby. He loved the dirt too, if ever he gets a chance on the surface he will be something.”

Moore and owner Peter Law will fly in Ryan Moore to partner the exciting Fastnet Rock gelding in the race, which the jockey came closest to winning when second on the Richard Gibson-trained Got Fly in 2015.

“Ryan Moore will come in to ride the horse,” Moore confirmed. “He’s the dark horse for the Derby. I’m not sure where he stands in comparison to the others. How good is he? I’m not sure. There’s a lot of upside there from a rating of 94, so he could turn out to be a real find, but he still has to prove it in this company.

“He’s done everything right and he’s a big, solid Fastnet Rock, so we’ll see what he can do. I’m really pleased with him going into the race.”

Moore has a strong Derby hand. Two of his charges with Group 1 wins already on the board also stepped out in this morning’s trials.

Helene Charisma (4th) and Eagle Way (8th) both went in batch nine, a 1600m turf trial, which also attracted fellow Derby contenders, the Danny Shum-trained Seasons Bloom (6th), placed in the Classic Mile and Classic Cup, and the John Size-trained pair of My Darling (2nd) and Dinozzo (10th).

Helen Charisma, last year’s G1 Grand Prix de Paris (2400m) winner, moved well, while G1 Queensland Derby (2400m) victor Eagle Way did all that was required.

“That was a good trial by Helene Charisma. Douglas (Whyte) was very happy and the horse enjoyed it,” Moore said.

“Eagle Way did what he had to do. There’s always a flat spot, which you could see at the 300 (metres), but Tommy (Berry) will ride him in the Derby and he knows all about that, he’ll stoke him up.”