Group One-winning filly Earthquake has never looked better as she prepares to try to keep a perfect Caulfield record in the Oakleigh Plate.

That's Godolphin racing manager Jason Walsh's assessment of last year's Blue Diamond winner who has been installed favourite for Saturday's Group One sprint.

Earthquake steps out for the first time since the spring in Saturday's 1100-metre race having won the Blue Diamond Stakes for two-year-olds at the corresponding meeting in 2014.

She has also won the Blue Diamond Prelude and a Group Three race for fillies last spring in her only other starts at Caulfield.

"She's never looked better," Walsh said.

"She's big and strong and extremely healthy so we're really excited to be stepping out a very talented filly again in what's going to be a very competitive Group One handicap.

"She's got a great record at Caulfield and her best would be the testing material."

Earthquake, who has 50.5kg, has drawn barrier 11 in the capacity field of 18 and will be ridden by Chad Schofield.

Schofield knows Earthquake has speed but doesn't expect to cross in front of I'm All The Talk and Lord Of The Sky who have drawn to Earthquake's inside.

"Hopefully we can get a bit of cover and I'm sure she'll be very strong to the line with no weight on her back," Schofield said.

Earthquake was the $4.80 favourite on Wednesday while Vain Queen tightened from an opening quote of $8.50 to $6 to be on the second line of betting.

Bel Sprinter, the 58kg topweight, will be giving weight to all his rivals and has the outside barrier but trainer Jason Warren is not fazed by either of those factors.

Bel Sprinter has had a habit of being slowly away and Warren is happy the $1 million earner will be among the last horses to be loaded in the barriers.

"I'd say I'd be more comfortable with barrier 18 than any other trainer in the race," Warren said.

"He'll probably begin well from 18 because he'll be in last, so it's probably not a bad thing.

"The horse is in such terrific order, they'll know he's there on Saturday."