Top Hong Kong-based rider Zac Purton teamed up with one of the world’s racing powerhouses to win his second Group One Doncaster Mile at Royal Randwick on It’s Somewhat for Godolphin on Saturday.

Purton, Joao Moreira and Sam Clipperton were all on duty on the opening day of The Championships in Sydney, but it was Purton who came away with the biggest result in Australia’s top 1,600m race.

On a track seen as favouring horses nearer the lead and the inside rail through the day, Purton bounced the John O’Shea-trained It’s Somewhat out of the gates with purpose, although not with the expressed intention of leading an event which is rarely won by frontrunners.

“It’s been hard to make up ground today. I went back and looked at the race he won here over 2,000 metres and I really liked the way he used his action,” said Purton, who added a second win in the A$3 million (HK$17.8m) Doncaster Mile to his victory on Sacred Falls in 2014.

“John said earlier in the day, ‘do you want to be positive?’ and I said ‘yep’. He said ‘good, he’s fit, so use his action’ The plan wasn’t necessarily to lead, but I got there comfortably and I just let him bowl along.”

O’Shea saddled up three runners in the race, with It’s Somewhat the least-fancied in the betting at over 30-1, and appeared to be overwhelmed by the surprise result after Purton’s mount held off the favourite, Happy Clapper.

Redkirk Warrior heavily backed to win the Doncaster Mile

The win gives Purton a prominent place in the very early stages of the Longines World’s Best Jockey list after wins in the Hong Kong Mile and Hong Kong Sprint count towards that award as well.

But if the Doncaster Mile was the nominal highlight race of the day’s racing, grey sprinter Chauatauqua provided the highlight in reality, producing a sensational last-to-first win to take his third successive Group One T J Smith Stakes under Tommy Berry.

Last year, Chautauqua came off his T J Smith to win the Chairman’s Sprint Prize at Sha Tin, but indications are that he will not take the same path this year.

One of his owners has already paid for a place in Sydney’s new race in October, The Everest, over 1,200m at Randwick, which will be the richest race on turf in the world in the format proposed and the grey will be targeting that instead.

Moreira came up with a blank at the prestigious meeting while Clipperton scored in a black type support race.