Anthony Cummings had to settle for second with two-year-old Diva Dee at Moonee Valley on Saturday but the stable posted a juvenile winner at Rosehill in the promising Never Can Tell.

The debutant showed the benefit of a recent barrier trial win when he settled well for Peter Robl and gathered in the leaders with ease to win the Sydney Markets Sprint (1100m).

Never Can Tell ($4.40) hit the line 2-3/4 lengths ahead of Velocity Miss ($13) with a head to The Oval Office ($51).

Favourite Sammy's Girl ($2.80) dropped out of the race, finishing 11 lengths from the winner and last of the six runners.

The daughter of champion filly Samantha Miss was later found to have suffered heart arrhythmia and will undergo an ECG and have to run in a barrier trial before she races again.

The winner is from the first crop left by War Pass, a Breeders' Cup Juvenile winner who stood two seasons at Widden Stud.

He was lost to the industry when he died of unknown causes on his return to Lane's End Farm in Kentucky in December 2010.

A resident of Gooree Stud, Never Can Tell's mother Chalee won two Listed races down the straight course at Flemington.

She has produced four winners but Never Can Tell is the first to win in the metropolitan area.

"He is a lovely little horse," Cummings's foreman Barry Smith said.

"He is just a natural. He is a bit small still."

The win brought up a race-to-race double for Robl and Cummings with Fiveandahalfstar winning the first race on the program.

Robl echoed Smith's assessment.

"He is a lovely horse," he said.

"He just wants to please you and that makes everything easier."