Gai Waterhouse has already made an impression on the Adelaide carnival and is looking to keep the momentum going.

Driefontein fulfilled her Group One destiny in Saturday's Robert Sangster Stakes (1200m) at Morphettville, beating last year's winner Platelet.

She now has two wins over the Darren Weir-trained mare and will be trying to keep her out again in the Group One Goodwood in two weeks.

Waterhouse also has the market leader for Saturday's South Australian Derby, VRC St Leger winner Order Of The Sun.

"It was a good win in the St Leger and he will go to the Derby," Waterhouse said.

"Driefontein will go back to Melbourne and then probably to the Goodwood.

"I sent her south a few weeks ago to let her acclimatise and get used to the opposite way of racing.

"She only cost $75,000 as a yearling and has won more than $2 million. She will be a very valuable brood mare."

The winner of the 2012 Magic Millions Classic, Driefontein beat Platelet by 1-1/4 lengths in the Group Three Robert Irwin (1100m) on April 12 and had her measure by the same margin in the Robert Sangster.

Order Of The Sun found weight-for-age company too strong in the Chipping Norton Stakes in March before striking wet tracks in the Rosehill Guineas and Tulloch Stakes.

Waterhouse sent him to Melbourne where he dominated Friday's VRC St Leger (2800m), leading all the way to beat Honey's Steel Gold by seven lengths.

Vlad Duric, who won the Robert Sangster on Driefontein, will replace Chad Schofield on Order Of The Sun in the Derby (2500m).

Schofield will be sidelined for the next couple of weeks due to suspension.

Order Of The Sun is the TAB's $3.80 SA Derby favourite ahead of Victorian Bring Something with Best Case and Gamblin' Guru at $7.

Waterhouse will travel to country Victoria this week for the three-day Warrnambool carnival.

The first of her runners will be Tenby Lady in Tuesday's maiden hurdle.

"I'm really looking forward to the `Bool," Waterhouse said.

"Tenby Lady is a mare originally from England and is a very good jumper."

Waterhouse was granted a jumps licence in time for last year's Warrnambool meeting but The Nemesis, who was to be her first runner over obstacles, went amiss before his scheduled race.