A winning treble at Flemington has given Craig Williams the lead in the Melbourne jockeys' premiership.

The treble provided Williams with his 50th metropolitan winner for the season and takes the four-time premiership winner to a one-win lead over Dwayne Dunn.

Damien Oliver, chasing a 10th title, scored on Amovatio in the sixth heat of VRC-CRV Winter Championship leaving him one victory further back.

Williams will be based in Melbourne for the remaining nine meetings of the season after scoring on the John Sadler pair of Bengal Cat and Lonrockstar before winning on Jessy Belle in the fourth heat of the Leilani Series.

"It's going to be a lot of hard work for my manager Mark Guest and myself to try and win this title," Williams said.

"I've ridden in Japan over the past five winters, so it's great to be a part of a tight finish to the season."

Oliver had missed the last four metropolitan meetings through injury and a trip to Royal Ascot before taking a short break to freshen for an end-of-season charge.

"It's a lot of travel and I wouldn't like to be doing it too often but it was a great experience and while I really enjoyed it, it's great to be back home," Oliver said.

He said the battle for premiership honours was provided a focal point for winter racing.

"It's unusual to see us top jockeys here at this time of year fighting it out as most of us are having a bit of a break," Oliver said.

"Obviously Craig and Dwayne are great jockeys and they can ride 54 (kilograms) which is a little harder for me to do at this time of the year.

"It's going to be a tough battle but whoever wins it will deserve it."

Amovatio will be aimed at the Winter Championship Final over 1600m at Flemington on July 11 following his 1-1/4 length victory over Decircles.

Trainer Sam Pritchard-Gordon scored his first Flemington success with the emotional win of Clemo in the Jeune Hanidcap while apprentice Boris Thornton landed his first metropolitan success, at his second ride in town, when Crafty Cruiser won the fifth heat of the Banjo Patterson Series.