Oasis Girl has relished a rise in distance and wet track with a commanding victory at Caulfield.

The Mathew Ellerton and Simon Zahra-trained filly strolled home under Jamie Kah to claim the Rod Fenwick Handicap (1600m) on Saturday.

Heavy rain on Saturday morning and during the early part of the Caulfield program resulted in the track being downgraded to heavy before Oasis Girl's race.

Oasis Girl won over 1400m on heavy ground at Caulfield on April 4 before a last-start sixth, beaten under two lengths, over 1400m at Flemington on April 25.

Riding the early speed, Oasis Girl ($4.40) shot clear on straightening recording a six length win from Lord Jaysea ($61) with Heyington Station ($7.50) a length away third.

Zahra said the stable had considered starting Oasis Girl in the Listed Adelaide Guineas (1600m) at Morphettville on Saturday before deciding to stay home and "take on the boys".

"The other day we just thought we chose the wrong race," Zahra said.

"She indicates that she just grinds away a bit over the 1400 metres and she really relished the conditions today and she's shown in the last month that stepping her up in distance isn't an issue.

"In her early days she used to pull in her work and we thought she was a bit of a sprinter, but she's come of age, she relaxes and she's got a nice cruising speed and turn of foot."