Sydney jockey Tim Clark continued his run of winning form in Hong Kong on Wednesday night as he drove home a double at Happy Valley, boosting his confidence ahead of his first ride in the Mercedes-Benz Hong Kong Derby on Sunday.

The Australian partners the John Moore-trained Smart Giant in the Group One Derby with the lightweight hoop believing he is a chance of causing an upset on his best form.

"I think I'm on a live chance in the Derby and it's great to get some confidence heading into the big race," Clark said.

Clark started with his first Hong Kong season with a flurry and scored a Group 2 win on John Moore's Destined For Glory in the Jockey Club Mile before the start of 2012 brought about a fruitless few months.

However he snapped a 65-ride winless run last week and showed his momentum had turned with the Happy Valley double, which started with the Caspar Fownes-trained Ride On The Fire's narrow victory in the opening event.

Ride On The Fire somehow repelled the challenges of Secret Of Winning and Gold Edition as they closed late, with the margins a nose by a nose in a near-triple dead heat.

"We looked good at the 75m, and then he started to walk," said Fownes, who said he would now look to claim, with the horse to climb to the top of Class Four.

Clark, who now has 14 winners for the term, showed he had learnt a thing or two about riding the Valley on Emperor Claudius, with a perfectly judged ride from gate 2 on the "C" course.

After finding the box seat behind stablemate Adoration, Clark patiently stuck to the fence and got

"Like most winners, he had thing go his way," said Size.

"That's just where this horse is at, he just needs a few things to go his way and he got that tonight with the barrier and the run he got in the race."

Jeff Lloyd also rode a double and clinched the Jockey Challenge on countback from Clark.

Lloyd won on Top Dragon for Me Tsui and John Moore's Charles The Great.

Peter Ho trained a double while Zac Purton was handed a two-meeting suspension for a careless riding charge.