While many of Sydney's leading riders plied their trade at the Gold Coast on Saturday, Blake Shinn made the most of his opportunities at Randwick to claim the premiership lead.

Shinn went into the meeting trailing Hugh Bowman by 1-1/2 wins and ended the day 1-1/2 in front.

The first two legs of his winning treble, She's Clean and Kaepernick, were relatively routine but he had to fight for his third in the stewards room.

Diametric finished a half head behind his Chris Waller-trained stablemate The Alfonso but stewards agreed Shinn had been impeded in the straight and took the race off Tye Angland.

It is the first time Shinn has been in front this season and he is determined to maintain the status quo but with his record of suspensions, he admits he has to be careful.

"Not being suspended will be my biggest challenge," Shinn said.

"I'm mindful of it but it's the first time I've been in front and it's exciting.

"It's going to be a good battle."

At almost the half-way point of the season, Shinn has ridden 46-1/2 winners to Bowman's 45 with reigning premier jockey James McDonald on 40-1/2.

McDonald rode two winners at the Gold Coast to Bowman's one.