Another dominant display by Appearance in the Canterbury Stakes has given the mare a fourth Group One victory and put a question mark over valuable colt Zoustar.

After missing the Chipping Norton Stakes (1600m) last week because of a mild case of the tying up problem which has dogged her career, Appearance came to Randwick on Saturday to run over 1300 metres.

With Kerrin McEvoy aboard for the first time this campaign, Appearance ($5.50) came from last on the turn with her now signature sprint to beat three-year-old Not Listen'tome ($4.40) by 1-1/4 lengths.

The first two starts of her preparation resulted in Group Two wins for Appearance in the Expressway and Apollo Stakes.

But that was not enough to take the hype off the return of Zoustar who was sent out the $4.20 favourite but could only manage eighth place.

While the colt's trainer Chris Waller was looking for answers, Appearance's trainer Guy Walter needs no telling how good Appearance is.

"She is an outstanding mare. Her record shows that," Walter said.

"She had a bit of a setback and missed the Chipping Norton but I took her to Kembla Grange for a gallop between races on Monday and I knew she was back on track.

"It is very satisfying."

It was also satisfying for Sheikh Mohammed's Darley Australia to see the mare take her record to nine wins from just 19 starts.

"Guy has done a wonderful job with her. She is one of the best mares in the country. She has beaten all the others," Darley managing director Henry Plumptre said.

Walter believes she is not only one of the best mares in the country but one of the best horses he has trained.

"She is getting up there with Tie The Knot. I didn't wake up in the morning thinking he would win 13 Group One races.

"But the good horses love to win and get better and better.

"We won't be backing her up in the Coolmore next week. It's up to Darley but thoughts are to go to the George Ryder the following week."

The George Ryder would set up a clash with the Waller-trained Chipping Norton winner Boban.

While Waller could offer little explanation for Zoustar's performance immediately after the race, stewards later reported the colt had pulled up a lame in a foreleg.

His next start is scheduled to be the $2.5 million TJ Smith Stakes (1200m) on April 12.