Her trainer's faith has never wavered and Streama has repaid Guy Walter with her third Group One win in Saturday's George Main Stakes at Randwick.

The race was a letdown for Jim Cassidy who had been striving for Group One win No. 100 on Hawkspur who finished fourth with Royal Descent and Veyron filling second and third.

The winner of the Flight Stakes and Australian Oaks as a three-year-old, Streama has run a string of placings since her victory in the Group Two Tristarc Stakes last spring.

"She is a fabulous mare," Walter said.

"She is very fit after an autumn and winter campaign. I think her fitness was the key."

That fitness was complemented by astute gear and program changes by Walter which helped Streama hold off her rivals under hard riding from Blake Shinn who steered her stablemate Toydini to victory in Wednesday's Cameron Handicap at Newcastle.

Walter decided not to run Streama in the Chelmsford Stakes after her hard run in last month's Warwick Stakes when she ran a close second to Veyron.

He also removed her blinkers for the George Main.

"I thought perhaps she hadn't seen the other horse in the Warwick Stakes and would be better without the blinkers," Walter said.

"I even thought she might lead today but she didn't have to."

Veyron ($20) led the field with Streama ($8.50) sitting behind him.

This year's Oaks winner Royal Descent ($5) made a late move but Streama was up to the task and went to the line strongly for her first Group One win against open company.

Toydini ($6) and Streama ($8) are two of the market leaders for the Epsom Handicap but unfortunately for Shinn he won't be able to ride either at their weights.

Toydini has 53kg and Stream 53.5kg with Shinn unable to ride under 55kg.

"I won't be able to ride either but I'm just so pleased to win this race for Guy," he said.

"I was able to control the tempo and I knew when I asked her to go she would."

Streama ran fourth in the Doncaster during the autumn and that race will be her aim again after the Epsom with Walter firm in his commitment to give her a spell after the big mile race.

"We want her to keep racing and the Doncaster is the race we have in mind," he said.

"After the Epsom she goes for a spell. She deserves it."