The $2.6 million half-sister to champion sprinter Black Caviar was beaten a short-half head by the Greg Eurell-trained Paddy's Gem in the AnimalS2U 3YO Fillies Maiden Plate (1100m).

"She'll take a lot of benefit from that run,'' O'Brien said of Belle Couture.

"She's not a rip and tear sprinter like Black Caviar.

"Today showed she's going to be better suited out over 1400m or a mile.

"That's probably a good thing because there's more options at those distances.

"Obviously we would have liked her to win...but we'll find another maiden for her now.

"I'd be very surprised if she didn't measure up to Group races in the spring."

Belle Couture's jockey Damien Oliver settled the filly midfield before making his run around the home turn.

The daughter of Redoute's Choice hit the front at the 200m mark and looked set for victory.

However, fellow first-starter Paddy's Gem ($7), ridden by Bendigo hoop Brad Rawiller,  wore down Belle Couture ($1.50 fav)in the shadows of the post.

"I wasn't disappointed with the run,'' Oliver said.

"Once she got to the front she waited a bit, but she kept fighting and on the line she was coming back at the winner.

"If the race had have been further she probably wins.

"It's not the worst thing that could happen. All the hype is out of the road and she can get on with being a racehorse."

Rawiller was confident the form out of the maiden would be strong.

"I thought I had the race won when we headed her (Belle Couture), but she showed a lot of fight to come back at us,'' Rawiller said.

"It was a tough job by mine (at her) first start to hold out at the finish.

"The stable was confident that my horse had good ability, they just weren't sure how good Belle Couture was."

Bendigo filly I'm An Outoftowner, trained by Rod Symons, made up good ground to finish a close-up third.

The first trio were seven lengths in front of the rest of the field.