GEELONG, Vic, Aug 24 AAP - Rockstardom, the $1.5 million son of three-time Melbourne Cup heroine Makybe Diva, has made a promising start to his racing career.

Stepping out in a three-year-old maiden race over 1300 metres at Geelong, Rockstardom finished fourth - about three lengths from the winner Eclair Surprise.

Rockstardom raced wide in a midfield position and was left flat-footed when the field sprinted for home.

But under the urgings of jockey James Winks, the flashy-looking colt settled into his work late in the race to just miss the minor placing.

Rockstardom was unwanted by on-course punters, drifting at every call from $2.50 to start at $5.

The lack of betting ring confidence reflected trainer Danny O'Brien's pre-race caution about Rockstardom's first-up chances.

"To be fair to the horse, to see the best of him we'll have to wait until he gets to 2000 metres and beyond," O'Brien said.

In a coincidence that could bode well for Rockstardom's future, Makybe Diva also finished fourth at her first start in a three-year-old maiden race at Benalla in country Victoria.

Her next outing in a 1600-metre maiden race at Wangaratta resulted in a victory, setting the mare on a path to greatness with a further 14 wins and $14.5 million in earnings.

Rockstardom is a result of her mating with 2001 English and Irish Derby winner Galileo.

He went through the 2009 Inglis Easter Yearling Sale for $1.5 million with breeder and Makybe Diva's owner Tony Santic retaining part-ownership in a syndicate.

To prove you don't have to spend big dollars to buy instant racetrack success, Eclair Surprise, also a first starter, realised a modest $65,000 when offered at a Perth Magic Millions sale last year.

Rockstardom is nominated for the Caulfield Guineas and O'Brien said the colt would also be a Victoria Derby entry.