Melbourne's reigning premier jockey Craig Williams has been a dominant force in Flemington Finals Day meetings in recent years and once again he is a major player.

Saturday's meeting is billed as 'Flemington Finals Day' because the races are a culmination of a number of different winter series races in Victoria in the past couple of months.

Williams rode six winners from the nine races at the corresponding meeting last year.

While he had to sit out the 2017 meeting because of a careless riding suspension, the champion hoop also bagged five winners at the 2016 meeting and three the year before that.

Williams' book of nine rides on Saturday includes South Australian visitor Waging War, who was the $4.20 favourite on Friday for the Listed Winter Championship Series Final (1600m), a race the jockey won last year on Magic Consul.

Waging War's co-trainer Leon Macdonald is confident the gelding, who he believes is racing in career-best form, will be hard to beat.

But Williams will need to overcome a wide draw (barrier 14 of 15) on the five-year-old who raced to the front at the 200m in a heat of the series over 1600m at Sandown three weeks ago, when ridden by Jamie Kah, only to be chased down in the final stride by Mr Marathon Man who is second favourite for Saturday's race.

"Last start at Sandown he did draw out in 11," Macdonald said.

"I know Sandown is a different track but he got into a good spot pretty quickly there. Whether that can happen on that long rounding turn at Flemington, I don't know, but I suppose that's up to the jockey.

"Craig is riding very, very well.

"He meets the horse that beat him the other day at Sandown one-kilo-and-a-half better which will help us a fair bit. And I'm sure Flemington will suit him."

Williams' book of rides also includes short-priced favourite Sure Knee in the Rivette Series Final for three-year-old fillies and stayer Future Score, who was the $3 favourite on race eve for the Banjo Paterson Series Final.

Williams has an 18-win lead over Damien Oliver in the Melbourne jockeys' premiership with six city meetings of the season remaining.

Oliver also has a top book of rides including short-priced favourite Buffalo River in the Silver Bowl Series Final.

He rides Mr Marathon Man in the Winter Championship Series Final.