With a Winx-free weekend of racing in Sydney, top jockey Hugh Bowman is in Melbourne with a genuine chance to plunder a big Group One double.

While the world's best horse on turf, Winx, isn't slated for her next start until Saturday week in Sydney, Bowman has the ride on favourite Spieth in the Newmarket Handicap (1200m) and leading Australian Cup chance Jameka on Saturday at Flemington.

Bowman's first Group One win came less than 13 years ago and he now sits on 59 elite-level wins in Australia with another three in Hong Kong.

He has been Australia's leading Group One rider for the past two seasons, as well as sharing the title with Kerrin McEvoy in 2012-13, and again leads this season's tally with six.

After Spieth was narrowly beaten by Terravista in the Lightning Stakes (1000m) at Flemington three weeks ago, Bowman is confident the Bryce Heys-trained sprinter can break through for an important Group One.

Spieth was also beaten a short margin in the Darley Classic at Flemington last spring.

"I think he's the horse to beat," Bowman said.

"I think he's going to be more effective at 1200 metres than 1000 metres. I don't think he has to improve to win, put it that way."

Spieth has the inside barrier in the straight track race.

Bowman isn't concerned jumping from the inside, but says what isn't ideal is that he has drawn on the opposite side to some of the horses he considers the main dangers.

"I would have preferred to have drawn around those other horses, but it's not the case," he said.

"Having ridden him in the Lightning I have more of an understanding of the horse now going into tomorrow."

He said he loved the way Spieth attacked the line after he got through a gap late in the Lightning.

Spieth is at $3.60 ahead ahead of three-year-olds Extreme Choice ($5) and Star Turn ($6.50).

Bowman was sounded out about riding Jameka during the spring of 2015, but rides the Ciaron Maher-trained Caulfield Cup winner in a race for the first time on Saturday.

Jameka is the $4 second favourite behind Humidor ($3.80) for the 2000m event.

"Hopefully we can get the job done," Bowman said.

"She looks beautifully placed. The race sets up well for her and she's obviously a top-class mare."

Bowman returns from a suspension on Saturday after almost two weeks on the sidelines.

"Naturally I'm looking forward to getting to the races," he said.

"I think I've ridden two meetings in three weeks. So let's hope I go well fresh."