Earthquake has confirmed her standing as a leading Blue Diamond contender with a convincing win in her first Melbourne start at Caulfield.

The Peter Snowden-trained two-year-old was sent out the $1.55 favourite in Saturday's Blue Diamond fillies Prelude (1100m) and raced clear to score by 2-3/4 lengths.

Snowden and jockey Damian Browne are adamant the exciting filly will be better again in two weeks in the Group One Blue Diamond.

"She's got natural ability and will take a lot from today's run," Snowden said. "The benefit from being around here today will be a big plus for her in a fortnight."

Snowden said the last 200m was the most exciting part of the win from Earthquake.

Browne looked to take a trail early but when the speed wasn't what he had hoped he kept going forward to sit outside the leader Eloping who had won the Blue Diamond fillies Preview two weeks ago.

"I know there's still a bit more left there for two weeks' time," Snowden said.

Browne picked up the ride for Saturday's Prelude when stable jockey Kerrin McEvoy ruled himself out with a knee injury earlier the week.

Earthquake took her record to two wins from as many starts, having won in style at Randwick on debut in November.