Steve Parnham's decision to ditch his family ties to ride three-year-old Ihtsahymn in the Group One Kingston Town Stakes at Ascot has paid off.

The jockey had ridden Playing God to two wins in the 1800m race for his trainer-father Neville Parnham but switched to the Fred Kersley-trained youngster on Saturday.

Steve Parnham said it had been the hardest decision of his life but his proud father said he had made the right one after Ihtsahymn held off Luckygray to win the final Group One race of the Australian year.

"It was a tough call for him and I'm very proud of him," Neville Parnham said.

Ihtsahymn races in the yellow and black colours of Oakland Stud made famous by the Kersley-trained champion Northerly who numbered the 2001 and 2002 Cox Plates among his achievements.

Kersley said perhaps Ihtsahymn, who also won the WA Guineas, could be a horse to bring to the eastern states.

"I'm tempted. I have fond memories of some races in Melbourne," he said.

"I'm very grateful to the Parnham family. It was a hard decision for Steve."

The jockey at the centre of the race admitted it was difficult to give up Playing God for Ihtsahym but with the former out of the placings, it worked out well.

"It was great effort by the horse," Steve Parnham said.

"He has taken a bit to mature and the blinkers switched him on.

"I'm very proud to win two Kingston Towns for Dad and one for Mr Kersley.

"It was an extremely tough decision and in the end I went for youth."

Parnham said he had no doubt the gelding could measure up in the east next year.