Peter and Paul Snowden have added another layer of depth to their autumn two-year-old arsenal with well-bred filly Cythera making a winning debut in the Lonhro Plate at Randwick.

An I Am Invincible half-sister to Group 1 placegetter Thronum, Cythera ($5.50) made the perfect start to her career with a narrow but decisive long head victory over Lady Laguna ($2.50 fav), who was brave in defeat after a wide run.

Spacewalk ($6) led and held third, another 1-1/4 lengths away.

The Snowdens are assembling a handy team of youngsters, led by Magic Millions runner-up Russian Conquest, and Paul Snowden says Cythera is a natural athlete who is open to vast improvement.

“She has always shown a nice bit of talent so we were pretty keen on her chances today, albeit knowing the fact that where she is mentally, she is just not there yet,” Paul Snowden said.

“When she hit the front, she just idled down, it wasn’t the other horse coming at her to a degree, it’s just her.

“She got the job done.

“She has got a good motor. The next six to 12 months are going to be the best thing for her but if it’s a little bit before her time, she will tell us.”

Winning jockey Tommy Berry echoed Snowden’s sentiments and said even if a race like the Golden Slipper comes too soon, Cythera’s racing future is bright.

“She has been (immature) the whole way through,” Berry said.

“She hasn’t been the one from day dot that jumped out of the ground and said, ‘this is going to be the best two-year-old’ but she has been the horse that has kept improving and there is a lot of substance about her.

“We were a bit worried about finding the front on her today because she does prick her ears and gets a bit lost.

“In a lot of her work, she comes from behind and works along well and that showed today. She looked the winner until she got there and she didn’t quite know how to finish it off.

“But it was a good effort and she is a lovely filly going forward.”

Snowden said they would let the dust settle before picking out Cythera’s next target.