Melbourne Cup day 2012 will be forever etched in Simon Vercoe's stable history with the Mornington trainer celebrating his first metropolitan win at Flemington.

Koonoomoo's victory in the Herald Sun Stakes (1400m) was also a Group Three triumph for Vercoe who prepares around 10 horses and had taken 10 years to break his city duck.

The five-year-old mare is a recent addition to Vercoe's team and her four starts for him had yielded two second placings before Tuesday.

"It is a great way to break my maiden status in town and to do it on this day is fantastic," Vercoe said.

"She is happy being ridden quietly and held up for a run and Hugh (Bowman) did just that.

"I've got about 10 horses in work at one time and she is the fastest by a mile.

"There will be a big celebration tonight, that's for sure."

Bowman brought Koonoomoo ($26) from the tail of the field and she pushed through to beat Cabernet ($13) by 1-1/2 lengths with Mid Summer Music ($8.50) another neck away third.

Favourite and early leader Sheila's Star ($5.50) weakened in the run home to finish 10th, almost six lengths from the winner.