A seven-year-old mare on a path to a jumping campaign has caused a major upset at Flemington, winning at a starting price of $151.

One For Later, trained by Allan Peterson at Warrnambool, surged clear of her rivals in the straight in Saturday's Dolly's Dream Handicap (2000m) to win by two lengths.

"It's great to win on a special day. I really don't know what to say," Peterson said.

"I mean, she was 150/1. She's going for a jumping career.

"The only thing I said to (apprentice jockey) Chris Caserta was to be forward, be on the pace, because she's a dour stayer.

"I said to the owners that she's extremely fit and she will run a cheeky race but I thought they were a bit classy for her today.

"We were putting her in this race to toughen her up for a 3000-metre race at the Valley."

Peterson is looking to take One For Later to the Oakbank carnival later this preparation for a jumps race.

Saturday's victory gave the 65-year-old former jockey, who has four horses in work, his first Flemington win as a trainer.

"I'm surprised she won," he said.

"But not surprised that she would run well because she was going into the race the fittest horse in the race."

One For Later was ridden by Chris Caserta who said he went into the race without any pressure on him but grew in confidence as it unfolded.

"It felt like a $2.80 favourite at the 800-metre mark," Caserta said.

"She just kept travelling for me. When the gap came on the inside, I just asked her to quicken and away she went and won like a good thing."

The race was named in memory of 14-year-old Amy "Dolly" Everett and jockeys wore special blue breeches in honour of the late teenager's favourite colour.

The objective was to raise awareness for the Dolly's Dream Foundation, which aims to facilitate programs and awareness surrounding bullying and youth suicide, enabling a positive change for other young lives.

"All the boys have come out here today to represent such an amazing girl," Caserta said.

"It's such a shame that no-one's put something in place for cyber bullying because it's happening all over the world and it's such a terrible thing that's happened."

Readers seeking support and information about suicide prevention can contact Lifeline on 13 11 14.