Trainer Grahame Begg has no doubt experience racing up the Flemington straight was a key ingredient to Mildred maintaining her unbeaten record at Flemington.

A debut winner over 900m at Flemington on September 25, Mildred added the Listed Maribyrnong Stakes (1000m) to her record on Saturday.

Her task was made easier with the scratching of the $3.10 favourite Deep Speed who was withdrawn at barrier.

Rider Luke Currie said Deep Speed felt sore on the way to the gates.

The scratching left a field of four with Mildred ($4.40) jumping straight to the front under jockey Jordan Childs recording a 1-1/2 length win from Jerle ($8) with Boom Daddy ($4.80) a head away third.

Begg explained original plans didn't take in Saturday's race, but after the filly did so well in her post-race recovery and taking into account the small nomination he decided to take up the challenge.

It also turned out to be the perfect birthday present for his mother Yvonne who turned 88 during the week.

Trained from his secondary Caulfield stable, Begg said Mildred may now head to his main stable at Pinecliff ahead of her next start.

"We were going to send her down to the farm at Pinecliff after her last start," Begg said.

"But I thought no, we may run this week, so we just put that on hold, but she may go down and have a bit of time chilling out at Pinecliff.

"Then we can either aim up at the Inglis Banner (at The Valley on Cox Plate day) or come back here for the Maribyrnong Plate.

"She's two from two here which is great going forward in the future."