Zac Purton has been given the green light to partner Exultant in Sunday’s Standard Chartered Champions & Chater Cup after working around the clock to overcome a back injury.

The Australian was stood down from his last seven rides at Happy Valley on Wednesday night with back spasms after saluting on Red Majesty, but has undergone regular treatment to ensure he could compete in the final Group One meeting of the Hong Kong season.

Purton and Exultant are shooting for a hat-trick of wins in the 2,400m feature while trainer Tony Cruz is also looking to continue his exceptional record in the race.

The 64-year-old has won seven of the past eight Champions & Chater Cups with the likes of Blazing Speed, California Memory, Helene Super Star and Pakistan Star.

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Cruz saddles up three of the eight runners – Time Warp and Packing Waltham are the other two – but there is no doubt Exultant is the leading hope in his trainer’s eyes.

The reigning Hong Kong Horse of the Year is yet to win a race this season, with four seconds, a third and a last-start fifth behind the Japanese visitors in the Group One QE II Cup.

But given he is only meeting a moderate group of opponents at set weights over his preferred trip, the HK$12 million feature looks right up his alley.

“I believe [he’s going well enough to win], there are no foreign horses around, that’s a big help,” Cruz said.

“I brought him to Conghua, so he’s really nice and fresh again. His trial was very good in Conghua. He seems to be all set.

“He’s getting on a bit in age and he seems to be slipping a bit. Zac came back after his last run and said he doesn’t seem to have that fight like he used to have – [when] he wouldn’t let another horse past him.

“So, I decided to send him to Conghua to freshen up. He can’t be tired. He’s fresh and ready for this race. I’ve freshened him up. I think he’s 100 per cent for this race, really.”

Exultant’s life was made even easier when the connections of Hong Kong superstar Golden Sixty opted to give him a break instead of tackling 2,400m for the first time.

“Obviously [Golden Sixty] would have been the main opposition, so I’m glad [trainer Francis Lui Kin-wai] made the decision not to run,” Cruz said.

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There is a chance the Champions & Chater Cup is Exultant’s swansong and Cruz is clear that he’s the best stayer he’s ever trained.

“He’s really a stayer, he’s got the one speed but he’s got a good heart,” Cruz said. “He won’t let another horse pass him – that’s really the ability that he’s got. He’s a top category horse, a Group One horse.

“He’s got speed and long distance. He hasn’t got early speed, but he’s got stamina. As a mile and a half horse, he’s the best one [I’ve had].”