After winning the Breeders' Plate with two-year-old colt Dubious earlier in the season, the Ciaron Maher and David Eustace stable has struck again with another nice juvenile in the Bumble Stakes for fillies at Flemington.

In a race run in driving rain to open the Melbourne Cup day program on Tuesday, Bella Rosa showed professionalism on debut to sit on the pace and stick her head out when it mattered to win the Group Three race by a half-head.

Bella Rosa was a $575,000 yearling purchase from this year's Magic Millions sale at the Gold Coast.

While the rich Magic Millions Classic in January is an option, Maher suggested he would look to target the Group One Blue Diamond Stakes instead with Bella Rosa.

"She's a cheap horse now," Maher said.

"The team and myself found her at the sales and there's a great bunch of owners in her.

"I'd like to thank the team. We hit the board with one of our two-year-old colts up in Sydney earlier in the year and now we've come here on a day like this and won with another two-year-old.

"Full credit to our breaker Adrian Corboy and our whole team.

"We really expanded the account and the budget and went after some more two-year-olds this year, so to hit the board here it's great."

Maher said Bella Rosa had always impressed him.

The Flemington track was downgraded to the heavy range immediately after the race as rain continued.

"Gee, it's wet," Bella Rosa's jockey Mark Zahra said.

"The surface water is quite substantial. Going up the straight there, we couldn't see much. I was lucky that I had an uninterrupted run."