Fiveandahalfstar has set up a mouth-watering clash against It's A Dundeel in next week's Australian Derby with an all-the-way success against older horses in the Group One BMW at Rosehill on Saturday.

Trainer Anthony Cummings bypassed last week's Rosehill Guineas with Fiveandahalfstar in favour of the $2.25 million BMW (2400m) the same distance as the Derby.

With Hugh Bowman replacing Peter Robl, Fiveandahalfstar took up his customary role in front.

Last year's Victoria Derby winner was taken on from well before the turn after controlling the speed, but he showed his toughness and quality as he fended off all his challengers including New Zealand stayers Silent Achiever and Sydney Cup-bound Sangster who filled the minor placings.

Fiveandahalfstar ($4.40 fav) became the first three-year-old since Grand Zulu in 2004 to win the BMW and the first Victoria Derby winner to come back in the autumn and take out Australia's only 2400m weight-for-age Group One.

He had a head to spare over Silent Achiever ($7.50) on the line with Sangster ($12) another length away.

It also gave Sydney's leading rider his second major of the day after Bowman scored on the Bart Cummings-trained Norzita in the Vinery Stud Stakes.

Fiveandahalfstar was run down by Foreteller in the final strides of the Ranvet Stakes two weeks ago for his fourth successive second of the autumn.

Both Bowman and Cummings can't wait to have a crack at dominant Rosehill Guineas winner It's A Dundeel in the Australian Derby (2400m) next Saturday.

"Oh, he'll beat It's A Dundeel," Bowman said with a smile just as It's A Dundeel's jockey James McDonald walked by after the BMW.

McDonald couldn't get the better of Fiveandahalfstar on Silent Achiever but believes he will next Saturday.

"I still win it," he said in response to Bowman.

Cummings praised Bowman and the horse who has now won more than $2.6 million prize money.

"Hugh played it right, took the backmarkers out of the game, found the best part of the track and the horse did the rest," Cummings said.

"It's a great result and a great day for the family."

Cummings said the Derby had the makings of a great race.

"They are the two dominant three-year-olds over ground here and I just hope we finish in front next week," Cummings said.

Silent Achiever's trainer Roger James said he was never confident of picking up the three-year-old but was proud of her effort.

"Off a slow pace she's come from last. It was a hellish run," James said.