An errant clod of dirt wasn't enough to stop veteran jockey Jim Cassidy from adding the Wyong Gold Cup to a long list of riding achievements on Friday.

Cassidy returned to scale in pain and looking worse for wear after Wazn landed a confident betting move to give trainer Chris Waller his third Cup win in four years.

"I got hit in the face with a round to go and I'm a little bit sore in the jaw but winning makes up for it," Cassidy said.

There was pain of a different kind felt by bookmakers as Wazn almost halved his quote in firming from $14 to $7.50.

In a sharp turnaround in recent fortunes for the latest in an endless line of European imports to win a feature race for Waller, Wazn produced a sweeping run to beat Peal Of Bells ($13) by a neck with the Wyong-trained Gazza Guru ($8) finishing a length away third.

The result was in stark contrast to his previous two starts when the seven-year-old couldn't beat a runner home.

As such, the Cup victory confirmed the horse's quirky nature as well as confirming Waller's reputation as a superior trainer of stayers.

"He is a tricky horse to work out really, he's all over the shop," stable spokesman Andy Cousins said.

"There are days when you can't figure out what he's up to and then there are days when he puts in like this."

Wazn settled at the tail of the eight-horse field but he was able to track into the race when the tempo lifted noticeably from the 800m.

The favourite Julienas ($3.20) worked into the picture but he soon laboured under his 61kg and was claimed by Gazza Guru.

Trying to win the race for the first time in four attempts, Gazza Guru established a small break but he had no answer for Wazn's finish before ultimately surrendering the runner-up spot to Peal Of Peals.

Cassidy, who will link with Waller to ride Shoot Out (Tramway Stakes) and Hawkspur (Chelmsford Stakes) at Randwick on Saturday, said the Rosehill trainer had few peers in Sydney racing.

"You can't underestimate Chris," he said. "It's a matter of getting them in the right race and getting them to click and Chris does it better than most."