Zac Purton found himself both delighted and nonplussed as the Tony Cruz-trained Exultant made himself the nominal Hong Kong Derby favourite with a scintillating win stepping up in distance at Sha Tin on Saturday.

Purton enjoyed a winning treble, entrusted with some of the more promising horses in town and made no mistake with Hot King Prawn and Exultant in the Class Twos and Win Beauty Win in the Griffin Trophy.

After two eye-catching runs at insufficient distances of 1,400m and 1,600m in Class One, Exultant got both a drop in class and the move to a more suitable distance of 2,000m and strolled in by almost three lengths.

But Purton was impressed by the win and shaking his head over the rising four-year-old’s manners in the run.

“You don’t often see horses pull that hard and still finish the race off like he did, so that bodes very well for the future, if he can sort himself out,” Purton said.

“I don’t think it was freshness – he’s had two runs plus some trials this season, and maybe it was the step from 1,600m to 2,000m the first time. It isn’t like they went slow for the first half, the tempo was actually quite nice and yet he was over-racing.

“That’s a concern but Tony is good at getting this sort of horse to switch off and relax, so I’ll let him work that out. Exultant has an engine but he’s six to 12 months away from being a proper horse and it will be hard to keep racing like that and get results.”

When pedigree and ‘Derby fever’ clashes with reality

An hour earlier, Purton had put the seal on Hot King Prawn’s racing for the time being when the unbeaten youngster graduated to Class Two, but this time without a wide margin of victory.

Owner Philip Lau Sak-hong has his fingers crossed for another Fairy King Prawn with the grey, and bloodstock agent David Price, who sold the three-year-old and also sold Silent Witness here, had an interesting comment on just how far Hot King Prawn has come quickly.

“If you think back to Silent Witness, it’s an interesting coincidence that Hot King Prawn won his fifth race today,” Price explained. “At this stage, Silent Witness was still a few days out from making his racetrack debut, on Boxing Day, in Class Four. At basically the same age, Hot King Prawn has won five races and has already won in Class Two.”

And that was one more win already than trainer John Size had intended after Hot King Prawn’s Class Three victory three weeks ago.

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“I had no intention of running him again for a while but this race was a bit too tempting. He got away with it but he is living proof of the difference between Class Three and Class Two,” Size said.

“He’s been putting up margins in the other races but in Class Two, you just can’t look as good. They can all gallop in Class Two, it’s that simple. That Pablosky that led today with him, he’s only won four races, all on the dirt, but wherever he runs he puts himself up the front and he’s a tough horse to get past. So Hot King Prawn had to fight him off and then hold any challengers late – I didn’t expect any more than that and I’m happy.

“Now he’ll have a good break, he might have a race or two towards the end of the season then we hope he comes back stronger as a four-year-old and see where he can go.”

Purton said the grey hit his limit at the line this time, in contrast to his easy wins prior.

“He was just starting to drop his head near the post,” he said. “He’s come a long way quickly and it’s probably a good thing that there’s not much around for him now so he can have a rest.”