Dwayne Dunn has boosted his chances of clinching his first Melbourne jockeys' premiership with a winning treble at Moonee Valley taking him to the front in the title.

Dunn knocked back the offer to ride Lumosty in Saturday's Tattersall's Tiara at the Gold Coast to remain in Melbourne.

His victories on Every Faith, Mawahibb and Alcohol in the Travis Harrison Cup have given him a one-win lead.

"You're giving up a Group One race but in saying that I don't get a chance at the premierships as much as I'd like, and I'm really competitive this year," Dunn said.

Dunn wasn't sure what a tough run in the Stradbroke would have taken out of Lumosty for the Tiara and said his decision to stay in Melbourne was "a toss of the coin".

"I knew I had a solid book of rides here, so it probably just swung me that way to stay here and as it has turned out it's been the right move so far," he said.

Not long after Alcohol raced to a 2-1/2 length win, Lumosty finished third up in the Tatt's Tiara.

Dunn started the meeting two wins behind Damien Oliver and Craig Williams who missed Moonee Valley due to Royal Ascot commitments.

There are 11 metropolitan meetings left in the season.

While the three high-profile jockeys are expected to battle it out for premiership honours, top apprentice Patrick Moloney has continued his charge with another two wins to take him to 41 for the season.

He has ridden seven winners at the past three Moonee Valley meetings and sits seven wins behind Dunn.

"I'll just keep on doing what I'm doing and the numbers will take care of themselves," Moloney said after winning on Word Of Mouth in the Brookfield Multiplex Handicap.

"Realistically, I don't think I can win the premiership," he said.

"It's pie-in-the-sky stuff. I've got to ride seven winners without Dwayne riding another winner."

Fellow apprentice Regan Bayliss fell foul of stewards, suspended for 12 meetings for not riding his horse Herstory right to the line when fourth in the race won by Moloney's mount Shakespearean Lass.