The youngest horses in the race have fought out the Australian Cup with Super Cool beating Fiveandahalfstar in the $1 million Flemington feature.

In an all three-year-old finish at the top end of the placings of the Group One race, Super Cool wore down his rival to win by a short head.

Surprisingly, it was Tanby who did best of owner Lloyd Williams's three runners after he made ground from last to finish third.

His late charge left Melbourne Cup-winning stablemate Green Moon in fourth position.

Super Cool raced fifth and tracked Green Moon into the race before he set out after Fiveandahalfstar.

Fiveandahalfstar established a clear break when he went to the front at the 300m and looked poised to add the Cup to his Victoria Derby win until Super Cool emerged with his run.

"Each time we've put him down (in a race) he has got better and better and better," Super Cool's trainer Mark Kavanagh said.

"To get a three-year-old to win at weight-for-age ... it's full credit to the horse."

Jockey Michael Rodd said Super Cool enjoyed the perfect run in the race.

"I thought if I could have average luck he would be too good for them," he said.