The opening race at the twilight city meeting at Caulfield has been won by the aptly named filly Twilight Song.

The well-bred Twilight Song ($7) was on debut in Wednesday's Ladbrokes Cash In (1100m) and made an immediate impression to win the maiden by three-quarters of a length from another first starter Masuta ($4.80 fav).

Over the next 10 weeks, Racing Victoria is trialling race-free Mondays across the state with a country meeting added earlier on Wednesdays.

Twilight Song is owned by her breeder Gerry Harvey and the three-year-old is by Fastnet Rock out of River Serenade whose progeny includes stakes-winning sprinter First Command.

"She's a beautiful big, strong filly," Lindsay Park's stable representative Bruno Rouge-Serret said.

"She's off to a good start."

Rouge-Serret said trainers David and Ben Hayes and Tom Dabernig were likely to give the filly her chance to snare black-type at some stage if she can keep stepping up.

"We're certainly going to aim that high with her," he said.

"She's certainly well-bred enough and on that debut win she's certainly capable of going on with it.

"The boys will pick out some nice races for her and have a crack at some black-type for sure."

Jockey Jake Duffy believes Twilight Song will take benefit from the experience.

Twilight Song was three-wide on the pace leading into the home straight and was able to rally to hold off Masuta on her outside and Spirit Of Aquada on her inside

"She was not that confident with putting the other horses away and I think she'll gain massive benefit from just learning a bit today," Duffy said.